1 . There was a time________people built the Great Wall to__________themselves from being________by the enemies.
那时候，人们建造长城来防止敌人的进攻。

2 . __________many times, the naughty boy still made the same mistake.

A．He had been told

B．Having been told

C．To be told

D．Having told

3 . ____ around the library, the visitors were taken to the playground.

A．Having shown	B．Having been shown
C．Being shown	D．To be shown

4 . The problem _________(discuss) now has something to do with us. (所给词的适当形式填空）

5 . At the beginning of class, the noise of desks ___ could be heard outside the classroom.

A．opened and closed	B．to be opened and closed
C．being opened and closed	D．to open and close

6 . The underground system ______(build) in the city will be open next year. (所给词的适当形式填空)

7 . To our great joy, the problem, _________for a number of years, has been settled recently.

A．having discussed

B．being discussed

C．having been discussed

D．to be discussed

8 . The building _____ will be completed in a month. It will be our lab building.

A．to paint

B．to have painted

C．being painted

D．painting

9 . Our teacher often tells us that the present efforts ___ in our future will be rewarded sooner or later.

A．investing

B．to invest

C．being invested

D．invested

10 . _________ from other continents for millions of years, Australia has many plants and animals not ________ in any other country in the world.

A．Having divided, to be found	B．Having been separated, found
C．Have been separated, found	D．Divided, finding