Aunt Lucy will tell us something about her trip to Australia when she______back.
A. came B. comes
C. would comeD. will come
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
