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.

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The passage suggests that methiocarb and metaldehyde would be more effective as slug poisons if it were true that they


disrupt the slug's digestive processes rather than its reproductive functions

reduce the slug's ability to taste food

begin to affect the feeding behavior of a slug only after it has ingested a lethal dose

reach the central pattern generator more quickly

accumulate only in the central pattern generator rather than throughout the brain

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题目分析：

题目释义：

细节题目

考点：

推断（Inference）
旨在考察我们对文章的深度理解，以及逻辑推断能力。

题目的意思其实让我们找出这两者的劣势，然后反过来就是答案了。定位在“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.”这两者的问题是鼻涕虫在吃到致命的剂量之前就被影响了饮食表现。所以，如果可以在致命剂量之后才影响饮食表现就可改进。


选项分析：

A选项：扰乱鼻涕虫的消化过程而不是繁殖功能。根据定位句可知，影响的是饮食表现而不是消化过程。

B选项：减少鼻涕虫的味觉能力。这个选项有一定的迷惑性。文中也没有提到过“味觉能力”。所以我们无法确认味觉是不是鼻涕虫不吃到致命剂量的原因。所以减少这样的能力不能确定是否会影响鼻涕虫吃到致命的剂量。

C选项：Correct. 只有达到了致命的剂量才开始影响鼻涕虫的饮食表现。考点中已经分析的很清楚了，此处不再赘述。

D选项：达到“central pattern generator”更快。这个选项说反了，如果更快的达到“central pattern generator”，鼻涕虫饮食表现受到的影响也就更快。

E选项：只在“central pattern generator”中累积而不是大脑中。不论在哪里累积，只要不能减缓影响饮食表现的时间，就无法让这两者的效果更大。

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Prep2007E2-RC