John didn’t give up looking for a job __________ he got an offer from a German company.
A. untilB. since
C. becauseD. if
— Would you like to go to the cartoon show with me?
— It sounds like fun, ______I’m too busy.
A. soB. for
C. orD. but
All passengers______go through safety check before they take a plane.
A. canB. may
C. mustD. ought
_____ carefully, Michael! There’s a school ahead.
A. DriveB. To drive
C. DroveD. Driving
Air pollution has become__________ than ever before. We must do something to stop it.
A. serious B. more serious
C. most serious D. the most serious
Old Mr. Black lives happily with his three dogs. of them are part of his family.
A. BothB. All
C. NoneD. Neither
