All the students in our class promised ____ the school rules.
A. follow B. follows C. following D. to follow
Our English teacher ____ in our school for about 20 years so far.
A. works B. has worked
C. worked D. will work
Drivers ____wear seat belts(安全带) while their cars are running on the road.
A. need B. can C. may D. must
I have to be off now. My friends _____outside.
A. wait B. are waiting
C. have waited D. were waiting
A lot of trees ____ around here every year， and we can enjoy fresher air now.
A. are planted B. were planted
C. will planted D. are planting
To protect the environment， supermarkets don’t ____free plastic bags to shoppers.
A. take B. show C. provide D. carry
