-To keep safe, everyone_______ wear a seat belt(安全带) in a car.A. is suppose B. are supposed to C. is supposed to D are supposed
He is very happy , because he _____ in a big apartment next year.
—How many birds can you see in the trees? —I can see _________ birds in them.
A dog robot could help ____ the room.
—Where is Miss Wang? —She went to Hainan Island last week and will return _________ six days.
There will be ____ cars and ____ pollution twenty years later.