单项选择
从A、B、C、D四个选项中选出可以填入空白处的最佳选项。
1. Now _____ your turn to give a speech.
A. there is B. there comes C. comes D. has come
2. —Jim can't finish homework until this Saturday.
—I know. ______.
A.I can't too. B.I can too. C. Neither can I. D. I can's neither.
3. ______ that air conditioners cause so much pollution, I would never have bought one.
A. Have I known B . If I have known C. If I knew D. Had I known
