The young people___________ jeans.
In recent years the environmental pollution has been _________ than before.
.It is said that a wooden bridge_________ over the river in the mountain village soon.
I’d like to travel by air _________ it usually costs a lot of money.
For the safety, everyone _________ obey the traffic rules when he is driving or walking.
This summer vocation I am going to do a lot of _________ to prepare for the senior high school.