你要看被动语态在句子里是不是谓语,不是谓语就直接用过去分词.
举例 The bridge built last year is destroyed by the storm.这里谓语是 destroy,所以用is destroyed.而The bridge built last year 这里build是做定语,解释这座桥.
你可以这样改The bridge destroyed by the storm was built last year.这样谓语就是build,destroy只是解释这座桥,做定语.
这两句话意思侧重点不同.第一句侧重说桥被毁,第二句侧重桥哪时侯建成的.哈，似乎挺有道理的谢啦