>
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。