[答案]　A

　　3．Scientists find from their studies that plants can ________.

　　A．predict natural disasters

　　B．protect themselves against insects

　　C．talk to one another intentionally

　　D．help their neighbors when necessary

　　[解析]　推理判断题。由文章的描述可知，当受到昆虫攻击时，有的植物会释放一种有难闻气味的化学物质来驱赶昆虫(Some plants pump out smelly chemicals to keep insects away.)，有的植物会释放香味引来袭击者的天敌(They pump out perfumes designed to attract different insects who are natural enemies to the attackers.)，无论哪种情况，都是为了保护自己，由此可知选B。A项所说的预测自然灾害，文中没有提及；C项属于曲解文意，原文说的是"Does this mean that plants talk to each other? Scientists don't know."，不是C项所说的"有意识地谈话"。由原文中的"Maybe the first plant just made a cry of pain or was sending a message to its own branches, and so, in effect, was talking to itseff."可知第一个遭受袭击的植物的本意并不是为了帮助邻居，故D项错误。

　　[答案]　B

　　4．What can we infer from the last paragraph?

　　A．The world is changing faster than ever.

　　B．People have stronger senses than before.

　　C．The world is more complex than it seems.

　　D．People in Darwin's time were more imaginative.

[解析]　推理判断题。最后一段告诉我们，达尔文在150多年前就想象世界要比我们感知的更繁忙、更吵闹、更亲密，由此可以推