Recently an unusually high number of dolphins have been found dead of infectious

游客2024-01-10  24

问题 Recently an unusually high number of dolphins have been found dead of infectious diseases, and most of these had abnormally high tissue concentrations of certain compounds that, even in low concentrations, reduce dolphins’ resistance to infection. The only source of these compounds in the dolphins’ environment is boat paint. Therefore, since dolphins rid their bodies of the compounds rapidly once exposure ceases, their mortality rate should decline rapidly if such boat paints are banned.
Which of the following, if true, most strengthens the argument?

选项 A、The levels of the compounds typically used in boat paints today are lower than they were in boat paints manufactured a decade ago.
B、In high concentrations, the compounds are toxic to many types of marine animals.
C、The compounds break down into harmless substances after a few months of exposure to water or air.
D、High tissue levels of the compounds have recently been found in some marine animals, but there is no record of any of those animals dying in unusually large numbers recently.
E、The compounds do not leach out of the boat paint if the paint is applied exactly in accordance with the manufacturer’s directions.

答案 C

解析 A.The levels of the compounds typically used in boat paints today are lower than they were in boat paints manufactured a decade ago.今天船漆所使用的化合物水平要比十年之前生产船漆所使用的低。
解析:根据该选项,要想降低海豚死亡率,只要使用今天生产的船漆即可,没有必要禁止使用船漆,该选项削弱原文,不选。
B.In high concentrations,the compounds are toxic to many types of marine animals.在高浓度下,化合物对于很多种类的海洋动物都有毒。
解析:该选项中的“很多种类的海洋动物”未必包含海豚。如果没有包含,则该选项与原文无关。如果包含海豚,就是在重复原文。逻辑题中重复原文的选项必错,不选。
C.The compounds break down into harmless substances after a few months of exposure to water or air.接触了水和空气几个月之后,化合物会降解成为无害的物质。
解析:禁止使用船漆之后,残留在海水中的化合物依然有可能继续感染海豚,加上该选项后,化合物会自行降解,因此就排除了“就算禁止使用船漆,化合物依然会有残留”这种额外因素。该选项属于“排除他因”加强,正确。
D.High tissue levels ofthe compounds have recently been found in some marine animals,but there is no record of any of those animals dying in unusually large numbers recently.最近在某些海洋动物中发现了高浓度的化合物,但是近期没有这些动物大量死亡的记录。
解析:该选项的问题在于“某些海洋动物”中是否包含海豚。如果包含,则削弱原文,否则与原文无关,不选。
E.The compounds do not leach out of the boat paint if the paint is applied exactly in accordance with the manufacturer’s directions.如果严格按照生产指示来使用的话,化合物不会从船漆中渗透出去。
解析:如果严格按照生产指示来使用,船漆就不会渗透出来,那么为了降低海豚死亡率,就没必要禁止使用船漆,只需要按照生产指示操作即可。不选。
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