can not的过去式

　　I could not work in these conditions any longer.

　　我再也不能在这样的环境中工作了。

　　He was emphatic that he could not work with her.

　　他强调他不能与她共事。

　　I could not bring myself to confront him about it.

　　我不能就此事让自己与他对质。