You can borrow at most four books from Xinghua Library ___________.
| A．at a time | B．from time to time | C．at times | D．in time |
In recent years the environmental pollution has been _________ than before.
| A．so serious | B．serious | C．more serious | D．too serious |
．It is said that a wooden bridge_________ over the river in the mountain village soon.
| A．build | B．will be built | C．will build | D．built |
I’d like to travel by air _________ it usually costs a lot of money.
| A．so | B．though | C．until | D．or |
For the safety, everyone _________ obey the traffic rules when he is driving or walking.
| A．need | B．must | C．may | D．could |
This summer vocation I am going to do a lot of _________ to prepare for the senior high school.
| A．job | B．work | C．invention | D．service |