The water froze inside the pipe，causing it to ________and burst.
| A．expand | B．export | C．reduce | D．behave |
Some insects_____ the colour of their surroundings (环境) to protect themselves.
| A．take up | B．take off | C．take on | D．take out |
_____ is known to everybody, the moon travels round the earth once every month.
| A．It | B．As | C．That | D．What |
We are invited to a party _________in our club next Friday.
| A．to be held | B．held | C．being held | D．holding |
It sounds like something is wrong with the car’s engine. ______ , we’d better take it to the garage immediately.
| A．Otherwise | B．If not | C．If possible | D．If so |
It is illegal for a public official (政府官员) to ask people for gifts or money_____ favors(恩惠，帮助) to them.
| A．in place of | B．in agreement with |
| C．in exchange for | D．in spite of |