4.修辞的需要，为了使句子更加简练、匀称

He appeared on the stage and was warmly applauded by the audience．

他出现在舞台上，得到了观众的热烈掌声。

The old professor gave a lecture on American history and waswell received．

这位老教授作了一个有关美国历史的讲座，受到了大家的热烈欢迎。

I was shown round the school campus by John，who had entered the school just a year before．

约翰带我参观了校园，他去年刚进这所学校。