—How about going for a drive now?
—______. I have been at home the whole day.
A. I'm sure B. I see C. I think so D. I agree
She wants to learn more about American history.She is thirsty______such knowledge.
A. at B. about C. on D. for
-- I can't find David. Where is he?
-- He ________ for tomorrow's competition at home.
A. prepares B. is preparing C. has prepared D. prepared
The rivers will become dirtier and dirtier ______ we take action to protect them.
A. since B. if
C. until D. unless
He often takes time______summer holiday with his grandparents.
A. to spend B. spend C. spent D. spending
Nobody can predict what in the future．So enjoy your life．
A. will happen B. Happen C. have happen D. happen
