—Winter swimming is exciting, but one can’t do it ________ he or she has got some training.
— Exactly! It can be dangerous.
A. after B. unless C. if D .while
（2017年贵州安顺） —Excuse me, sir, smoking _____ in the gas station.
—Oh, I'm awfully sorry.
A. doesn't allow B. is allowed C. aren't allowed D. isn't allowed
— Look at the sign! You aren’t allowed _______ in public places.
— Sorry, I didn’t see it.
A. smoke B. smoking C. to smoke D. smoked
Don't ________ the lift. Something has gone wrong with it.
A. get into B. get to C. get out of D. get on
Look at the“No Photos”sign.You______take photos in the art museum.
A. should B. can C. needn’t D. mustn’t
It is _________ difficult question that _______ students can answer it.
A. such, a few B. so. Few C. such a , few D. such a , a few
