定位第2段：An endangered population is always rare（对应A）, almost always small（对应B）, and, by definition, under constant threat of extinction （对应C）even without a proximate cause in human activities（对应E）. 选D
A They are among the rarest kinds of amphibians.
B They generally have populations that are small in size.
C They are in constant danger of extinction.
D Those with decreasing populations are the most likely candidates for immediate extinction.
原文相反，第二段最后一句：The probability of extinction due to such random factors depends on the population size and is independent of the prevailing direction of change in that size
E They are in danger of extinction due to events that sometimes have nothing to do with human activities.
Many fairly common amphibian species declared all but extinct after severe declines in the 1950s and 1960s have subsequently recovered, and so might the apparently declining populations that have generated the current appearance of an amphibian crisis. 定位到这句话了，说许多1950年代的A在下降后恢复了，所以现在处在下降危机中的A也许也会recover。 和 C相反，故选C.1 0 回复 2020-08-16 11:38:05
题干说true of endangered amphibian species，已经将范围限制到endangered。 文章区分了两种不同的情境，主要是为了解释将一种现象简单归结到其中一种情境的不合理之处。 但是既然题干已经将这种现象中的物种归结到一种情境中，那么就应该按照这种情境中的特征来回答问题。 谨记。0 0 回复 2016-12-30 13:41:32