—Dad, why must I stop ____ computer games?
—For your health, my boy.
A. play B. to play C. to playing D. playing
--Do you enjoy a volunteer?
--If you want this，you’d better join us．
A. being，knowing B. to be，knowing
C. being，to know D. to be，to know
I invited her together, but she didn’t agree.
A. sing B. singing C. to sing D. sings
Have you met Mr Li ?
A. just B. ago C. before D. a moment ago
Mr Lin asked us questions in English，not in Chinese．
A. answer B. to answer C. answering D. to answering
We find________impossible for us to learn a foreign language well in a short time．
A. that
B. this
C. one
D. it
