You shouldn’t accept a lift from a person ________ you don’t know him.
A. until B. unless C. if D. whether
—Will you join us in the discussion? —Well, I won’t join you unless Wang Lin ________ too.
A. will be asked B. is asked C. asked D. be asked
One thousand people died in the disaster, ________ two hundred and fifty-five children.
A. were included B. including C. include D. included
According to the air traffic rules, you ______ switch off your mobile phone before boarding.
A . ought to B. may C. can D. would
Shirley a book about China last year and it sells well now.
A. has written B. was written C. had written D. wrote
The teacher asked the students to do the experiment _____ small groups.
A. to B. for C. on D. in
