Most farmers attempting to control slugs and snails turn to baited slug poison, or molluscicide, which usually consists of a bran pellet containing either methiocarb or metaldehyde.Both chemicals are neurotoxins that disrupt that part of the brain charged with making the mouth move in a coordinated fashion--the "central pattern generator"--as the slug feeds. Thus, both neurotoxins, while somewhat effective, interfere with the slugs' feeding behavior and limit their ingestion of the poison, increasing the probability that some will stop feeding before receiving a lethal dose.Moreover, slugs are not the only consumers of these poisons:methiocarb may be toxic to a variety of species, including varieties of worms, carabid beetles, and fish.
Researchers are experimenting with an alternative compound based on aluminum, which may solve these problems, but this may well have a limited future as we learn more about the hazards of aluminum in the environment.For example, some researchers suggest that acid rain kills trees by mobilizing aluminum in the soil, while others have noted that the human disease Alzheimer's is more prevalent in areas where levels of aluminum in the soil are high.With farmers losing as much as 20 percent of their crops to slugs and snails even after treatment with currently available molluscicides, there is considerable incentive for researchers to come up with better and environmentally safer solutions.
The passage suggests that methiocarb and metaldehyde would be more effective as slug poisons if it were true that they
(A) disrupt the slug's digestive processes rather than its reproductive functions
(B) reduce the slug's ability to taste food
(C) begin to affect the feeding behavior of a slug only after it has ingested a lethal dose
(D) reach the central pattern generator more quickly
(E) accumulate only in the central pattern generator rather than throughout the brain
答案是C，不理解耶，文中给的信息是“Thus, both neurotoxins, while somewhat effective, interfere with the slugs' feeding behavior and limit their ingestion of the poison, increasing the probability that some will stop feeding before receiving a lethal dose.”
C跟文中相反的嘛，我选的是A。
望NN们来帮忙答疑解惑，谢谢啦~
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