—Sir, could you please put out your cigarette? This is a smoke-free (无烟的) school.
—______
A. I'm sorry about this. B. No problem.
C. Sure, I'd love to. D. Never mind.
—How often do you chat with your friends online?
— . I'm busy with my study.
A. Only one month. B. About twice a month.
C. Almost every day. D. Maybe in two weeks.
the children have fun, parents can take dance lessons on the beach.
A. When B. If C. While D. Once
The World Health Organization has given some advice on to protect us from being infected(感染) with H7N9.
A. how B. what C. where D. when
—Linda, I called you this morning, but nobody answered the phone.
—I'm sorry. I football with my friends then.
A. play B. played C. am playing D. was playing
—Why do you collect so many old bikes?
—I'Il have them _ and give away to the children who don't have bikes.
A. used up B. given up C. fixed up D. set up