havebeendone是什么时态

回答

爱扬教育

2022-09-28

have been done是现在完成时的被动结构。
例句：
Something ought to have been done before now.
先前就该采取措施了。
How could it have been done?
这怎么可能做得到呢？

扩展资料

　　What could have been done better?

　　有哪些本可以做的更好？

　　It could have been done carefully.

　　它可能被小心地搜寻过。

　　But no studies have been done in WOMEN.

　　但没有对女人进行的研究。