【考例】(2005广东) The American Civil War lasted four years the North won in the end.

A. after B. before C. when D. then

[考查目标] 时间状语从句的引导词选择。

[答案与解析]B before 表示“直到……”。

4. Tree after tree went down, cut down by the water, which must have been three meters deep. 洪水想必深达三米，树一棵接一棵地倒了，被洪水冲断了。

该句中的must have been表示推测。例如：You look so tired. You must have stayed up last night.

情态动词may，might，most.can，could常用来表示推测。may，might，must多用在肯定句中，can，could多用在否定句和疑问句中。may，might，must，can，could后接动词原形表示对现在的推测;may，might，must，can，could后接have done。表示对过去的推测。例如：

You may be a professor. / She must have met a fairy.

【考例】(2005辽宁)This cake is very sweet. You ____ a lot of sugar in it.

A. should put B. could have put

C. might put D. must have put

[考查目标] 情态动词表示推测。

[答案与解析] D 前文说蛋糕很甜，由此可知一定是糖

放多了。对于过去的动作的推测应使用have done的

结构，所以应在B、D之间做选择，又因为could have

done表示本可以做而没有做，所以选择D。

5. ... she heard a loud noise，which grew to a terrible roar. ……她听见了很响的声音，接着就变成了可怕的隆隆轰鸣声。

该句中的which引导非限制性定语从句。例如：He bought some reference books, which were all about science. 他买了许多的参考资料.都是有关理科的。

which 作为关系代词.既可以引导限制性定语从句，也可以引导非限制性定语从句。例如：The train which left for Beijing pulled in on time. 前往北京的火车按时进站了。His dog, which was now very old, became ill and died.他的狗，现在老了，生病死了。

【考例】(2005浙江) Jim passed the driving test, ____ surprised everybody in the office.

A. which B. that C. this D. it

[考查目标]非限制性定语从句。

[答案与解析]A which引导非限制性定语从句。指代

前面整个句子。that不能引导非限制性定语从句。