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.
Humans have struggled against weeds since the beginnings of agriculture. Marring our gardens is one of the milder effects of weeds - any plants that thrive where they are unwanted. They clog waterways, destroy wildlife habitats, and impede farming. Their spread eliminates grazing areas and accounts for one-third of all crop loss. They compete for sunlight, nutrients, and water with useful plants.
The global need for weed control had been answered mainly by the chemical industry. Its herbicides are effective and sometimes necessary, but some pose serious problems, particularly if misused. Toxic compounds threaten animal and public health when they accumulate in food plants, groundwater, and drinking water. They also harm workers who apply them.
In recent years, the chemical industry has introduced several herbicides that are more ecologically sound. Yet new chemicals alone cannot solve the world's weed problems. Hence, scientists are exploring the innate weed-killing powers of living organisms, primarily insects and microorganisms.
The biological agents now in use are environmentally benign and are harmless to humans. They can be chosen for their ability to attack selected targets and leave crops and other plants untouched. In contrast, some of the most effective chemicals kill virtually all the plants they come in contact with, sparing only those that are naturally resistant or have been genetically modified for resistance. Furthermore, a number of biological agents can be administered only once, after which no added applications are needed. Chemicals typically must be used several times per growing season.
With what topic does this passage primarily deal?
A. The importance of the chemical industry.
B. The dangers of toxic chemicals.
C. A proposal to ban the use of all herbicides.
D. Advantages of biological agents over chemical ones.
Đáp án : D
THông tin:
- In recent years, the chemical industry has introduced several herbicides that are more ecologically sound.
- The biological agents now in use are environmentally benign and are harmless to humans
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Mark the letter A, B, C or D on your answer sheet to show the underlined part that needs correction in each of the following questions.
Animals and man (A) use the energy finding (B) in food to operate (C) their body and (D) muscles.
Mark the letter A, B, C or D on your answer sheet to show the underlined part that needs correction in each of the following questions.
Not until much (A) later did she realize (B) that her long-known (C) partner had been lying her. (D)
The weather is going to change soon; I feel it in my _________ .
He suddenly saw Sue ________ the room. He pushed his way ________the crowd of people to get to her.
The city_________at one time prosperous, for it enjoyed a high level of civilization.
I’ve never had the slightest disagreement ________ him __________ anything.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase for each of the blanks
One of the hottest topics on the international development agenda is how to harness the power of International Monetary Fund for the benefit of developing countries. What is sometimes called “the death of distance”, brought about by the (55) , allow professional services such as (56)______education and training to be provided easily and quickly to (57) areas. Some of the gains can be seen in countries as diverse as India and Morocco, where innovations range from (58) _________ government announcements to local craftsmen selling their wares to a (59)________market. But already a huge and expanding (60) _________ divide is opening up between developed and developing nations. The major tasks facing world leaders at present is to (61) ________ everybody on the planet with clean water, basic education and the drugs needed to fight preventable diseases. Installing a (62)______in every classroom and linking us to (63) must be a lesser (64)_______, for the time being at least.
Điền vào ô 61
More than a mile of roadway has been blocked with trees, stones and other debris, ______ the explosion.
Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part is pronounced differently from that of the rest in each of the following questions
Mark the letter A, B, C or D on your answer sheet to show the underlined part that needs correction in each of the following questions.
A basic (A) knowledge of social studies, such as history (B) and geography, are (C) considered a basic part of the education of every child. (D)
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.
Humans have struggled against weeds since the beginnings of agriculture. Marring our gardens is one of the milder effects of weeds - any plants that thrive where they are unwanted. They clog waterways, destroy wildlife habitats, and impede farming. Their spread eliminates grazing areas and accounts for one-third of all crop loss. They compete for sunlight, nutrients, and water with useful plants.
The global need for weed control had been answered mainly by the chemical industry. Its herbicides are effective and sometimes necessary, but some pose serious problems, particularly if misused. Toxic compounds threaten animal and public health when they accumulate in food plants, groundwater, and drinking water. They also harm workers who apply them.
In recent years, the chemical industry has introduced several herbicides that are more ecologically sound. Yet new chemicals alone cannot solve the world's weed problems. Hence, scientists are exploring the innate weed-killing powers of living organisms, primarily insects and microorganisms.
The biological agents now in use are environmentally benign and are harmless to humans. They can be chosen for their ability to attack selected targets and leave crops and other plants untouched. In contrast, some of the most effective chemicals kill virtually all the plants they come in contact with, sparing only those that are naturally resistant or have been genetically modified for resistance. Furthermore, a number of biological agents can be administered only once, after which no added applications are needed. Chemicals typically must be used several times per growing season.
According to the passage, biological agents mainly consist of _______.