[求助]求大虾帮忙解两道题

1. Potato cyst nematodes are a pest of potato crops. The nematodes can lie dormant for several years in their cysts, which are protective capsules, and do not emerge except in the presence of chemicals emitted by potato roots. A company that has identified the relevant chemicals in planning to market them to potato farmers to spread on their fields when no potatoes are planted; any nematodes that emerge will soon starve to death.

Which of the following, if true, best supports the claim that the company's  plan will be successful?

A. Nematodes that have emerged from their cysts can be killed by ordinary pesticides.

B. The only part of a potato that a nematode eats is the roots.

C. Some bacteria commonly present in the roots of potatoes digest the chemicals that cause the nematodes to emerge from their cysts.

D. Trials have shown that spreading even minute quantities of the chemicals on potato fields caused nine-tenths of the nematodes present to emerge from their cysts.

E. the chemicals that cause the nematodes to emerge from their cysts are not emitted all the time the potato plant is growing.

选D

2. In the United States, vacationers account for more than half of all visitors to what are technically called "pure aquariums" but for fewer than one quarter of all visitors to zoos, which usually include a "zoo aquarium" of relatively modest scope.

Which of the following, if true, most helps to account for the difference described above between visitors to zoos and visitors to pure aquariums?

A. In cities that have both a zoo and a pure aquarium, local residents are twice as likely to visit the aquarium as they are to visit the zoo.

B. Virtually all large metropolitan areas have zoos, whereas only a few large metropolitan areas have pure aquariums.

C. Over the last ten years, newly constructed pure aquariums have outnumbered newly established zoos by a factor of two to one.

D. People who visit a zoo in a given year are two times more likely to visit a pure aquarium that year than are people who do not visit a zoo.

E. The zoo aquariums of zoos that are in the same city as a pure aquarium tend to be smaller than the aquariums of zoos that have no pure aquarium nearby.

选B

请求帮忙解答，谢谢！