Problem
If
y
is 45 percent of
x
and
z
is 25 percent of
x
, what is
y
+
z
in terms of
x
?
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PSAT: Critical Reading Question #3 |
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This passage, except for many of the authorial value judgments, is based on Environmental Protection Agency documents on the environmental impact of the pesticide methyl bromide and its planned phase-out.
Although many organizations-especially those connected to the agricultural industries-maintain that the benefits of methyl bromide outweigh its risks, methyl bromide is a toxic chemical that will poison, not only the target pests it is used against, but non-target organisms as well. Because it dissipates so rapidly into the atmosphere, this pesticide is most dangerous at the actual fumigation site, where human exposure to high concentrations is at a maximum. This exposure can result in central nervous system and respiratory system failure, as well as specific and severe deleterious actions on the lungs, eyes, and skin. Exposure of pregnant women may result in fetal defects. Depending upon dose, gross permanent disabilities or death may result.
Assessments made by atmospheric scientists, under the authority of the World Meteorological Organization along with the National Oceanic and Atmospheric Administration and the National Aeronautics and Space Administration, indicate that methyl bromide also contributes significantly to the destruction of earth's stratospheric ozone layer, which protects life on earth from exposure to dangerous levels of ultraviolet light, a major cause of skin cancer, cataracts, and impaired immune systems. When ozone-degrading chemicals such as methyl bromide (whose sources include soil fumigation, as mentioned above, as well as the exhaust of automobiles using leaded gasoline) are emitted, the chlorine and bromine they contain catalyze destruction of the ozone.
Worldwide, most of the methyl bromide used goes to fumigate soil for preplant purposes. The breakdown is 70 percent to fumigate soil, 16 and 8 percent to fumigate durable and perishable commodities, respectively, and 6 percent to treat structures. Of all the methyl bromide used, North America uses the most, at 43 percent of the total. Asia uses 24 percent and Europe 24 percent, while the remaining 9 percent is used by Africa, South America, and Australia. In the United States, growers use 43 million pounds of methyl bromide each year. Of that, about 35 million pounds go for soil fumigation, 5 million for post-harvest uses, and 3 million for structural fumigation. This means that 81 percent of the chemical used goes to prepare the soil for vegetables, orchards, nurseries, and other crops-that is, 81 percent actually affects foods we take into our bodies.
Because science has so definitely fingered methyl bromide as a culprit in destroying the ozone, regulatory actions are needed to control emissions. Under the Clean Air Act, methyl bromide had been scheduled for phase-out in the United States on January 1, 2001. In spite of its obvious hazards, however, much of the agricultural industry continues to lobby against discontinuing utilization of this pesticide, and Congress recently signed legislation to extend its use, beginning gradual phase-out by 2005.
Question:
In the context of the passage, to which of the following does the term "fumigation site" (line 10) refer?
Choices:
The correct answer is (C). Choices (B) and (E) do not describe a site (or location). Although toxicity might be high at choices (A) and (D), it makes most sense that the toxicity would be highest at the place where the pesticide is actually added to the soil.
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