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17. GWD28-Q17:
In the nation of Partoria, large trucks currently account for 6 percent of miles driven on Partoria’s roads but are involved in 12 percent of all highway fatalities.The very largest trucks—those with three trailers—had less than a third of the accident rate of single-and double-trailer trucks.Clearly, therefore, one way for Partoria to reduce highway deaths would be to require shippers to increase their use of triple-trailer trucks.
Which of the following, if true, most seriously weakens the argument?
A.Partorian trucking companies have so far used triple-trailer trucks on lightly traveled sections of major highways only.
B.No matter what changes Partoria makes in the regulation of trucking, it will have to keep some smaller roads off-limits to all large trucks.
C.Very few fatal collisions involving trucks in Partoria are collisions between two trucks.
D.In Partoria, the safety record of the trucking industry as a whole has improved slightly over the past ten years.
E.In Partoria, the maximum legal payload of a triple-trailer truck is less than three times the maximum legal payload of the largest of the single-trailer trucks.
The Answer is A, I cannot understand this logic at all.
28. GWD28-Q28:
Which of the following most logically completes the argument?
A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants.Agronomists studying the herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert.Possibly, therefore, the herb’s high histidine production is what allows it to grow in metal-rich soils, a hypothesis that would gain support if ______.
A.histidine is found in all parts of the plant—roots, stem, leaves, and flowers
B.the herb’s high level of histidine production is found to be associated with an unusually low level of production of other amino acids
C.others of the closely related group of plants are also found to produce histidine in large quantities
D.cultivation of the herb in soil with high concentrations of the metals will, over an extended period, make the soil suitable for plants to which the metals are toxic
E.the concentration of histidine in the growing herb declines as the plant approaches maturity
The answer is C, but why D is not correct?
Thank u
28. GWD28-Q28:
Which of the following most logically completes the argument?
A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants.Agronomists studying the herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert.Possibly, therefore, the herb’s high histidine production is what allows it to grow in metal-rich soils, a hypothesis that would gain support if ______.
A.histidine is found in all parts of the plant—roots, stem, leaves, and flowers
B.the herb’s high level of histidine production is found to be associated with an unusually low level of production of other amino acids
C.others of the closely related group of plants are also found to produce histidine in large quantities
D.cultivation of the herb in soil with high concentrations of the metals will, over an extended period, make the soil suitable for plants to which the metals are toxic
E.the concentration of histidine in the growing herb declines as the plant approaches maturity
The answer is C, but why D is not correct?
Thank u
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发表于 2011-8-1 11:29:45
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