build的过去式过去分词和名词

　　Huge palaces were built by slave labour.

　　宏伟的宫殿是奴隶建成的。

　　The school has recently built a new gym.

　　学校最近新建了一个体育馆。

　　It was built at the turn of the century.

　　这是在世纪之交修建的。