1 . If the electric light ________ invented, people ________ in darkness during night at that time.

A．were not; could have lived	B．were not; could live
C．had not been; could have lived	D．had not been; could live

2 . I wish I        the Great Wall with you tomorrow, but I’m preparing for the coming exam.

A．would climb

B．had climbed

C．to climb

D．will climb

3 . Jacob ________ with several of his colleagues on a big project and they still have a long way to go.

A．has worked

B．works

C．was working

D．has been working

6 . When hearing the funny joke, they ________ laughter and talked away on end for hours.

A．burst out

B．burst into

C．turn to

D．turn down

7 . ________ many times, he finally understood it.

A．Having told

B．To be told

C．Being told

D．Having been told

8 . Kate heard a man’s voice in the background, but she couldn’t ________ what she was saying.

A．make up

B．make of

C．make out

D．make from

9 . ______ in his experiment, he didn’t hear the knock on the door.

A．Absorbing

B．Being absorbed

C．To be absorbed

D．Absorbed

10 . At first he refused to admit ______ in the exam, but when he was shown the evidence he ______ and admitted it.

A．to cheat; broke down	B．to cheat; broke away
C．cheating; broke away	D．cheating; broke down