The word "it" in bold in paragraph 2 refers to___________.

The word "immutable" in line 18 is closest in meaning to

The phrase “the former“ refers to…

The example “You cant make a silk purse out of a sows ear” is used to...

Which of the following is mentioned as one of the purposes of the Fair Labor Standards Art of 1938?

What is one reason for the change in the length of the workweek for the average worker in the United States during the 1930's?

According to the passage, creatures in the desert

The word “rather” is closest in meaning to….

It can be inferred from the passage that the early life of a flatfish is____

According to the paragraph 2, what will NOT happen if one breathes the toxic air?

The word "henceforth" in line 11 is closest in meaning to

We can infer from the passage that

In which environment would you NOT expect a Pfiesteria bloom to develop?

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.

Pollution is a threat to many species on Earth, but sometimes it can cause species to thrive. Such is the case with Pfiesteria piscicida. A one-celled creature called a dinoflagellate, Pfiesteria inhabits warm coastal areas and river mouths, especially along the eastern United States. Although scientists have found evidence of Pfiesteria in 3,000-year-old sea floor sediments and dinoflagellates are thought to be one of the oldest life forms on earth, few people took notice of Pfiesteria.

Lately, however, blooms – or huge, dense populations – of Pfiesteria are appearing in coastal waters, and in such large concentrations the dinoflagellates become ruthless killers. The blooms emit powerful toxins that weaken and entrap fish that swim into the area. The toxins eventually cause the fish to develop large bleeding sores through which the tiny creatures attack, feasting on blood and flesh. Often the damage is astounding. During a 1991 fish kill, which was blamed on Pfiesteria on North Carolina’s Neuse River, nearly one billion fish died and bulldozers had to be brought in to clear the remains from the river. Of course, such events can have a devastating effect on commercially important fish, but that is just one way that Pfiesteria causes problems. The toxins it emits affect human skin in much the same way as they affect fish skin. Additionally, fisherman and others who have spent time near Pfiesteria blooms report that the toxins seem to get into the air, where once inhaled they affect the nervous system, causing severe headaches, blurred vision, nausea, breathing difficulty, short-term memory loss and even cognitive impairment.

For a while, it seemed that deadly Pfiesteria blooms were a threat only to North Carolina waters, but the problem seems to be spreading. More and more, conditions along the east coast seem to be favorable for Pfiesteria. Researchers suspect that pollutants such as animal waste from livestock operations, fertilizers            washed from farmlands and waste water from mining operations have probably all combined to promote the growth of Pfiesteria in coastal waters.

What is true of Pfiesteria?

Which of the following best characterizes the organization of the passage