25. What can we infer from the last paragraph?

　　[A] Monkeys can be trained to develop social emotions.

　　[B] Human indignation evolved from an uncertain source.

　　[C] Animals usually show their feelings openly as humans do.

　　[D] Cooperation among monkeys remains stable only in the wild.

　　[第21题答案及题解页数] C 第页

　　[第22题答案及题解页数] B 第页

　　[第23题答案及题解页数] A 第页

　　[第24题答案及题解页数] C 第页

　　[第25题答案及题解页数] B 第页

　　[长难句突破]

　　However, when two monkeys were placed in separate but adjoining chambers, so that each could observe what the other was getting in return for its rock, their behaviour became markedly different.

　　主体句式：Their behaviour became markedly different.

　　结构分析：本句的主干成分非常短，而且位于句子的最后。该句的主要部分是when引导的时间状语从句，从句中又包含了一个以so that引导的目的状语从句，用来说明与前文内容相关的目的。

　　However, whether such a sense of fairness evolved independently in capuchins and humans, or whether it stems from the common ancestor that the species had 35m years ago, is, as yet, an unanswered question.

　　主体句式：Whether… or whether… is an unsnwered question.

　　结构分析：本句的主语非常长，即两个以wehther引导的并列结构“whether such a sense of fairness evolved independently in capuchins and humans, or whether it stems from the common ancestor that the species had 35m years ago”。此外，主句中的谓语和宾语之间又多了一个插入语，更加增加了迷惑性。辨别本句的关键就是找对主句。