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
________ call me Mimi! It's my cat's name.
A. Not B. Didn't C. Doesn't D. Don't
