be done是什么時態的被動語態

　　Nothing could be done without her say-so.

　　未經她準許，什么都不可以做。

　　She insisted that everything be done over.

　　她堅持全部返工。

　　Everything could be done by a nod and a wink.

　　每件事只靠點撥一下就能辦妥了。