题目

题型：同步题难度：来源：

基本语法。
1. I haven"t heard from him ______ he went to America.
2. He won"t be here______he is invited.
3. He will not go to the cinema ______he is very busy.
4. We found the key ______she had left it.
5. We found the books two days ______he had gone away.

答案

1. since   2. unless   3. because   4. where   5. after