单选题
A worldwide ban on the production of certain ozone-destroying chemicals would provide only an illusion of protection. Quantities of such chemicals, already produced, exist as coolants in millions of refrigerators. When they reach the ozone layer in the atmosphere, their action cannot be halted. So there is no way to prevent these chemicals from damaging the ozone layer further. Which of the following, if true, most seriously weakens the argument above?
【正确答案】
E
【答案解析】[解析] 本题读题重点应放在最后两句话上。推理前提为“When they reach...”,结论为:“So there is no way to...”。反对重点反对前提。若冰箱中的制冷剂可以在冰箱完成使命后被完全开发并重新使用,正如(E)所说,那么这些制冷剂就不可能到达臭氧层,所以(E)反对了前提,因此(E)为正确答案。(A)中的“the quantity”,(B)中的“refrigeration of food”均与推理无关;(C)、(D)均起到部分支持作用。