时态是完成时态。

例句：

The marshes have been drained. 

沼泽地里的水已排干。

Your trip must have been fun! 

你这次旅行一定很开心吧！ 扩展资料

Things have been going badly.

事情进展得不顺利。

How could I have been so stupid?

我怎么会这么傻

You could have been killed!

你本可能被杀了。