单选题 A report on acid rain concluded, "Most forests in Canada are not being damaged by acid rain." Critics of the report insist the conclusion be changed to, "Most forests in Canada do not show visible symptoms of damage by acid rain, such as abnormal loss of leaves, slower rates of growth, or higher mortality."
Which of the following, if true, provides the best logical justification for the critics' insistence that the report's conclusion be changed?

A、 Some forests in Canada are being damaged by acid rain.
B、 Acid rain could be causing damage for which symptoms have not yet become visible.
C、 The report does not compare acid rain damage to Canadian forests with acid rain damage to forests in other countries.
D、 All forests in Canada have received acid rain during the past fifteen years.
E、 (E) The severity of damage by acid rain differs from forest to forest.

【正确答案】 B

【答案解析】[解析] 上面的段落隐含的推理可以提炼成“由于没有明显症状，所以酸雨没有造成危害”，本题让我们去反对这种说法以支持批评者的观点。如果酸雨可能正在造成症状尚未明显的危害，如(B)所说，那么就把前提A与B断开，表明A与B无联系，因此也就实现了问题目的，所以(B)正确；(A)中的“some”作为个案，只能反对绝对，不能反对一般，若把some改为many，即可起到反对作用；(C)是一个无关比较；(D)只表明“receive”，但“receive”不一定“被破坏”；(E)同样也是无关选项。