一、1.Vocabulary and Structure

0. I will be back tomorrow______there is a plane strike.

A．butB．andC．unlessD．if not

1. ______you are not busy, could you help me with this work?

A．BecauseB．As long asC．AlthoughD．In order that

2. ______you have learned Spanish, you will find Italian much easier.

A．AlthoughB．SinceC．OnceD．As soon as

3. You can go out to play______you stay in the backyard.

A．supposingB．as long asC．ifD．though

4. ______you call me to say you are not coming, I will see you at the theater.

A．IfB．SinceC．AlthoughD．Unless

5. They don"t like the city______they found it too noisy and polluted.

A．asB．forC．now thatD．because

6. The journey there was terrible, but______we"d arrived we had a wonderful time.

A．untilB．whenC．onceD．as

7. We got wet in the rain______none of us had brought along a raincoat.

A．soB．becauseC．in order thatD．when

8. ______he starts a job, he won"t stop until it is finished.

A．OnceB．AfterC．UntilD．As soon as

9. You can borrow the bike______you bring it back.

A．unlessB．ifC．sinceD．providing

10. Don"t promise anything______you are 100 percent sure.

A．ifB．sinceC．unlessD．because

11. I don"t mind your watching TV______it doesn"t take too much time.

A．untilB．sinceC．as long asD．even if

12. You must be very careful when handling these acids______they are very concentrated.

A．asB．whenC．ifD．while

13. A body,______it is in motion, would never stop itself if there were no friction.

A．tillB．whenC．beforeD．once

14. ______he had done it, he knew it was a mistake.

A．SinceB．In order thatC．As long asD．As soon as