will/shall have done是什么時態

　　We will have done the job ahead of time if it doesn't rain.

　　如果不下雨，我們定能提前完成這項工作。

　　Most of us will have done this at some point, many of us still do.

　　我們很多人都在某些情況下這么做過，很多人仍然在做。

　　Even if they prevail, however, Mr Perez's bill will have done some good.

　　然而，即便他們獲得了勝利，佩雷斯的法案仍將帶來一些益處。