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 author cites which of the following as a disadvantage of methiocarb?
It contains high levels of aluminum.
It may react with acid rain to kill trees.
It has been associated with Alzheimer's disease.
It may be toxic to some species of fish.
It may not be as effective in killing slugs as metaldehyde is.
题目分析:
题目释义:
细节题目
考点:
支持主题(Supporting ideas)
旨在考察我们对文章细节的认知
根据题设定位在“methiocarb may be toxic to a variety of species, including varieties of worms, carabid beetles, and fish.”,第一段的最后一句话。
选项分析:
A选项:它含有大量的铝。第二段开篇就说了,含有铝的化合物可以解决问题。如果“methiocarb”中有铝,就不会有第一种方法的问题,也不会提出第二个方法了。
B选项:它会和酸雨反应杀死树木。文中只提到了酸雨本身可以杀死树木,没有提及什么和酸雨一起作用杀死树木。
C选项:它会和酸雨反应杀死树木。文中只提到了酸雨本身可以杀死树木,没有提及什么和酸雨一起作用杀死树木。
D选项: Correct. 它可能会对某些种类的鱼有毒。几乎是定位句的直译。
E选项:它可能在杀鼻涕虫方面没有“metaldehyde”那么有效。文中没有比较过这两者的杀虫能力。
定位精准即可。
学会给长句断句很重要。doing修饰名词,表示“带有”,done表示“被完成”的。
methiocarb may be toxic to a variety of species, including varieties of worms, carabid beetles, and fish.