I don’t know ______ with this problem. It’s too hard.
Chongqing ______ a lot in the past few years.A.has changed B. changed C. is changing
Mr. Smith didn’t tell us ______.A. where he lives B. where he lived C. where did he live
—How many people did you see in the meeting room? — ______.A. Nothing B. No one C. None
— Your bike is very beautiful. How long ____you _____it? — Just two weeks.A. have; bought B. did; buy C. have; had
—Look! What a nice classroom! — Yes, it ________ every day.A. is cleaning B. has cleaned C. is cleaned