Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

Mark the letter A, B, C or D on your answer sheet to indicate the word that differs from the rest in the position of the main stress in each of the following questions.

Mark the letter A, B, C or D on your answer sheet to indicate the word that differs from the rest in the position of the main stress in each of the following questions.

I don’t know much about computer, so I asked the assistant for____________advice.

You should know that everyone in this office____________busy planning the dance for a week.

The children were made____________up the mess they had left before they could watch TV.

Most headaches____________with aspirin unless they are too severe.

I wish I____________able to accept that role, but I was preparing for another play at the time.

Everyone thought she would accept the offer. ____________, she turned it down immediately.

I would have cooked something special if I____________you were coming.

Women have proved repeatedly that they are equal and often superior____________men in almost every field.

There is still widespread____________against older people in the job market.

The arrested man is suspected of____________government funds for himself.

It was hard to____________the temptation to watch the late-night show even though I was so tired then.

The company managed to beat the ____________on delivering its new system.

Even though she had been studying hard, she had only a____________chance of passing the exam.

I ran in a marathon last week, but I was not fit enough. I____________after 15 kilometres.

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

Keith had so interesting and creative plans that everyone wanted to work on his committee.

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

Air pollution, together with littering, are causing many problems in our large, industrial world.

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

A paragraph is a portion of a text consists of one or more sentences related to the same idea.

Mark the letter A, B, C or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.

Greater use of public transport would cut the amount of pollution from cars.

Mark the letter A, B, C or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.

Mark delayed writing the book until he had done a lot of research.

Mark the letter A, B, C or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.

“Would you like to come out to dinner with me tonight, Jenny?” Paul said.

Mark the letter A, B, C or D on your answer sheet to indicate the sentence that best combines each pair of sentences in the following questions.

Lee gave up her job. She planned to continue her education.

Mark the letter A, B, C or D on your answer sheet to indicate the sentence that best combines each pair of sentences in the following questions.

This is a rare opportunity. You should take advantage of it to get a better job.

Mark the letter A, B, C or D on your answer sheet to indicate the most suitable response to complete each of the following exchanges.

Mark and Anne are talking after the class.

Mark: “Guess what? I’ve been recruited to be a member of Green Dream Volunteer Group.”

Anne: “____________”

Mark the letter A, B, C, or D on your answer sheet to indicate the word or phrase that is CLOSEST in meaning to the underlined part in each of the following questions.

Amy and Jacob are talking about the two-day excursion at the end of the school year. Amy: “You look so sad. ____________”

Jacob: “I couldn’t get my parents’ permission to stay the night away from home.”

Mark the letter A, B, C, or D on your answer sheet to indicate the word or phrase that is CLOSEST in meaning to the underlined part in each of the following questions.

It was late at night, the wind was howling and when she heard the knock on the door, she almost jumped out of her skin.

Mark the letter A, B, C, or D on your answer sheet to indicate the word or phrase that is CLOSEST in meaning to the underlined part in each of the following questions.

Wild animals use various methods to ward off predators and their natural enemies.

Mark the letter A, B, C, or D on your answer sheet to indicate the word or phrase that is OPPOSITE in meaning to the underlined part in each of the following questions.

We should grow more trees so that they can absorb more carbon dioxide from the atmosphere.

Mark the letter A, B, C, or D on your answer sheet to indicate the word or phrase that is OPPOSITE in meaning to the underlined part in each of the following questions.

We have achieved considerable results in the economic field, such as high economic growth, stability and significant poverty alleviation over the past few years.

Read the following passage and mark the letter A, B, C or Don your answer sheet to indicate the correct word for each of the blanks from 33 to 37.

Everyone wants to reduce pollution. But the pollution (33) ____________is as complicated as it is serious. It is complicated because much pollution is caused by things that benefit people. (34) ____________, exhaust from automobiles causes a large percentage of air pollution. But the automobile provides transportation for millions of people. Factories discharge much of the material that pollutes the air and water but factories give (35) ____________to a large number of people.

Thus, to end or greatly reduce pollution immediately, people would have to (36) ____________using many things that benefit them. Most people do not want to do that, of course. But pollution can be gradually reduced in several ways. Scientists and engineers can work to find ways to lessen the amount of pollution that such things as automobiles and factories cause. Governments can pass and enforce laws (37) ____________require businesses and traffic to stop, or to cut down on certain polluting activities.

Read the following passage and mark the letter A, B, C or Don your answer sheet to indicate the correct word for each of the blanks from 33 to 37.

Everyone wants to reduce pollution. But the pollution (33) ____________is as complicated as it is serious. It is complicated because much pollution is caused by things that benefit people. (34) ____________, exhaust from automobiles causes a large percentage of air pollution. But the automobile provides transportation for millions of people. Factories discharge much of the material that pollutes the air and water but factories give (35) ____________to a large number of people.

Thus, to end or greatly reduce pollution immediately, people would have to (36) ____________using many things that benefit them. Most people do not want to do that, of course. But pollution can be gradually reduced in several ways. Scientists and engineers can work to find ways to lessen the amount of pollution that such things as automobiles and factories cause. Governments can pass and enforce laws (37) ____________require businesses and traffic to stop, or to cut down on certain polluting activities.

Read the following passage and mark the letter A, B, C or Don your answer sheet to indicate the correct word for each of the blanks from 33 to 37.

Everyone wants to reduce pollution. But the pollution (33) ____________is as complicated as it is serious. It is complicated because much pollution is caused by things that benefit people. (34) ____________, exhaust from automobiles causes a large percentage of air pollution. But the automobile provides transportation for millions of people. Factories discharge much of the material that pollutes the air and water but factories give (35) ____________to a large number of people.

Thus, to end or greatly reduce pollution immediately, people would have to (36) ____________using many things that benefit them. Most people do not want to do that, of course. But pollution can be gradually reduced in several ways. Scientists and engineers can work to find ways to lessen the amount of pollution that such things as automobiles and factories cause. Governments can pass and enforce laws (37) ____________require businesses and traffic to stop, or to cut down on certain polluting activities.

Read the following passage and mark the letter A, B, C or Don your answer sheet to indicate the correct word for each of the blanks from 33 to 37.

Everyone wants to reduce pollution. But the pollution (33) ____________is as complicated as it is serious. It is complicated because much pollution is caused by things that benefit people. (34) ____________, exhaust from automobiles causes a large percentage of air pollution. But the automobile provides transportation for millions of people. Factories discharge much of the material that pollutes the air and water but factories give (35) ____________to a large number of people.

Thus, to end or greatly reduce pollution immediately, people would have to (36) ____________using many things that benefit them. Most people do not want to do that, of course. But pollution can be gradually reduced in several ways. Scientists and engineers can work to find ways to lessen the amount of pollution that such things as automobiles and factories cause. Governments can pass and enforce laws (37) ____________require businesses and traffic to stop, or to cut down on certain polluting activities.

Read the following passage and mark the letter A, B, C or Don your answer sheet to indicate the correct word for each of the blanks from 33 to 37.

Everyone wants to reduce pollution. But the pollution (33) ____________is as complicated as it is serious. It is complicated because much pollution is caused by things that benefit people. (34) ____________, exhaust from automobiles causes a large percentage of air pollution. But the automobile provides transportation for millions of people. Factories discharge much of the material that pollutes the air and water but factories give (35) ____________to a large number of people.

Thus, to end or greatly reduce pollution immediately, people would have to (36) ____________using many things that benefit them. Most people do not want to do that, of course. But pollution can be gradually reduced in several ways. Scientists and engineers can work to find ways to lessen the amount of pollution that such things as automobiles and factories cause. Governments can pass and enforce laws (37) ____________require businesses and traffic to stop, or to cut down on certain polluting activities.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 38 to 42.

By adopting a few simple techniques, parents who read to their children can considerably increase their children's language development. It is surprising, but true. How parents talk to their children makes a big difference in the children's language development. If a parent encourages the child to actively respond to what the parent is reading, the child's language skills increase.

A study was done with two or three-year-old children and their parents. Half of the thirty children participants were in the experimental study; the other half acted as the control group. In the experimental group, the parents were given a two-hour training session in which they were taught to ask open-ended questions rather than yes-no questions. For example, the parent should ask, "What is the doggy doing?" rather than, "Is the doggy running away?" Experimental parents were also instructed how to expand on their children's answer, how to suggest alternative possibilities, and how to praise correct answers.

At the beginning of the study, the children did not differ on levels of language development, but at the end of one month, the children in the experimental group were 5.5 months ahead of the control group on a test of verbal expression and vocabulary. Nine months later, the children in the experimental group still showed an advance of 6 months over the children in the control group.

Parents can give great help to their children's language development by____________them.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 38 to 42.

By adopting a few simple techniques, parents who read to their children can considerably increase their children's language development. It is surprising, but true. How parents talk to their children makes a big difference in the children's language development. If a parent encourages the child to actively respond to what the parent is reading, the child's language skills increase.

A study was done with two or three-year-old children and their parents. Half of the thirty children participants were in the experimental study; the other half acted as the control group. In the experimental group, the parents were given a two-hour training session in which they were taught to ask open-ended questions rather than yes-no questions. For example, the parent should ask, "What is the doggy doing?" rather than, "Is the doggy running away?" Experimental parents were also instructed how to expand on their children's answer, how to suggest alternative possibilities, and how to praise correct answers.

At the beginning of the study, the children did not differ on levels of language development, but at the end of one month, the children in the experimental group were 5.5 months ahead of the control group on a test of verbal expression and vocabulary. Nine months later, the children in the experimental group still showed an advance of 6 months over the children in the control group.

what does the word "they" in the second paragraph refer to?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 38 to 42.

By adopting a few simple techniques, parents who read to their children can considerably increase their children's language development. It is surprising, but true. How parents talk to their children makes a big difference in the children's language development. If a parent encourages the child to actively respond to what the parent is reading, the child's language skills increase.

A study was done with two or three-year-old children and their parents. Half of the thirty children participants were in the experimental study; the other half acted as the control group. In the experimental group, the parents were given a two-hour training session in which they were taught to ask open-ended questions rather than yes-no questions. For example, the parent should ask, "What is the doggy doing?" rather than, "Is the doggy running away?" Experimental parents were also instructed how to expand on their children's answer, how to suggest alternative possibilities, and how to praise correct answers.

At the beginning of the study, the children did not differ on levels of language development, but at the end of one month, the children in the experimental group were 5.5 months ahead of the control group on a test of verbal expression and vocabulary. Nine months later, the children in the experimental group still showed an advance of 6 months over the children in the control group.

During the training session, experimental parents were taught to____________.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 38 to 42.

By adopting a few simple techniques, parents who read to their children can considerably increase their children's language development. It is surprising, but true. How parents talk to their children makes a big difference in the children's language development. If a parent encourages the child to actively respond to what the parent is reading, the child's language skills increase.

A study was done with two or three-year-old children and their parents. Half of the thirty children participants were in the experimental study; the other half acted as the control group. In the experimental group, the parents were given a two-hour training session in which they were taught to ask open-ended questions rather than yes-no questions. For example, the parent should ask, "What is the doggy doing?" rather than, "Is the doggy running away?" Experimental parents were also instructed how to expand on their children's answer, how to suggest alternative possibilities, and how to praise correct answers.

At the beginning of the study, the children did not differ on levels of language development, but at the end of one month, the children in the experimental group were 5.5 months ahead of the control group on a test of verbal expression and vocabulary. Nine months later, the children in the experimental group still showed an advance of 6 months over the children in the control group.

what was the major difference between the control group and the experimental one in the study?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 38 to 42.

By adopting a few simple techniques, parents who read to their children can considerably increase their children's language development. It is surprising, but true. How parents talk to their children makes a big difference in the children's language development. If a parent encourages the child to actively respond to what the parent is reading, the child's language skills increase.

A study was done with two or three-year-old children and their parents. Half of the thirty children participants were in the experimental study; the other half acted as the control group. In the experimental group, the parents were given a two-hour training session in which they were taught to ask open-ended questions rather than yes-no questions. For example, the parent should ask, "What is the doggy doing?" rather than, "Is the doggy running away?" Experimental parents were also instructed how to expand on their children's answer, how to suggest alternative possibilities, and how to praise correct answers.

At the beginning of the study, the children did not differ on levels of language development, but at the end of one month, the children in the experimental group were 5.5 months ahead of the control group on a test of verbal expression and vocabulary. Nine months later, the children in the experimental group still showed an advance of 6 months over the children in the control group.

What conclusion can be drawn from this passage?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.

Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.

Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significantly greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.

However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperatures were too high and particles of matter were moving around much too rapidly. It was only after the one- minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased

What does the passage mainly explain?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.

Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.

Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significantly greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.

However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperatures were too high and particles of matter were moving around much too rapidly. It was only after the one- minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased

According to the passage, helium is____________.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.

Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.

Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significantly greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.

However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperatures were too high and particles of matter were moving around much too rapidly. It was only after the one- minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased

The word “constituents” is closest in meaning to____________.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.

Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.

Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significantly greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.

However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperatures were too high and particles of matter were moving around much too rapidly. It was only after the one- minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased

Why does the author mention “cosmic rays”?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.

Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.

Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significantly greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.

However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperatures were too high and particles of matter were moving around much too rapidly. It was only after the one- minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased

The word “they” refers to____________

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.

Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.

Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significantly greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.

However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperatures were too high and particles of matter were moving around much too rapidly. It was only after the one- minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased

The word “vary” is closest in meaning to____________.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.

Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.

Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significantly greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.

However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperatures were too high and particles of matter were moving around much too rapidly. It was only after the one- minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased

The creation of helium within stars____________.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.

Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic rays are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn’t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.

Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significantly greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.

However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperatures were too high and particles of matter were moving around much too rapidly. It was only after the one- minute point that helium could exist. By this time, the universe had cooled so sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formations of helium went on for only relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased

Most of the helium in the universe was formed____________