分词短语做定语在大多数情况下都可与定语从句相转换.这是非谓语动词的语法特点.
The school which was built twenty years ago is our school=The school built twenty years ago is our school
但完成式的现在分词短语不能用作定语.如果两个动作有先后,要用定语从句.
误：This is one of the factories having been built in 1980.
正：This is one of the factories that were built in 1980.
正：This is one of the factories built in 1980.