not.until 与not.beforeI could not finish the homework________.A.until he has come B.before he cameC.when he comes D.by he had come选那一个?为什么?着重介绍not until 和not..before的区别,
问题描述：
not.until 与not.before
I could not finish the homework________.
A.until he has come B.before he came
C.when he comes D.by he had come
选那一个?为什么?
着重介绍not until 和not..before的区别,
答
until he has come 强调直到.才 是一种临界状态
直到他回来我才完成作业
before he came 强调再他回来之前 我没法完成作业