The scientists will succeed in their experiment______ they give up.
A. unless B. if C. after D. until
Michael’s mother never makes him______his room. He does it by himself.
A. cleaningB. cleans C. to clean D. clean
Jill_______be in the office now. She has gone to the reading room.
A. can’t B. mustn’tC. needn’tD. shouldn’t
My family are going to have a party to celebrate my grandpa’s ______birthday.
A. ninety B. ninetiesC. ninetiethD. ninetieths
The Medal of freedom is the highest ______that an American can get.
A. championship B. contribution C. awardD. product
Many people make ______a rule to send cards to their friends before Christmas.
A. themselves B. it C. that D. this
