——Can you tell me why________?
——Because I want to help the people there.
A. do you go to Tibet（西藏） B. did you go to Tibet
C. are you going to Tibet D. you are going to Tibet
They went to the park yesterday, ________?
A. don't they B. didn't they
C. aren't they D. can't they
She________ know the answer, but I'm not sure.
A. maybe B. may be C. may D. must
Chinese________ by the largest number of people.
A. is speaking B. speak
C. speaks D. is spoken
Now China has joined WTO（世贸组织）, so I think English is________ useful than before.
A. more B. most C. much D. many
Mr. Black is rich, ________ he is not happy.
A. and B. or C. but D. 不填
