----- Let` s learn to use the problem we are facing ___ a stepping-stone to future success.

a. to　 b. for　 c. as d. by

_________(口译者)are people who change spoken words from one language to another, specially as their job.

The two sides reached a partial agreement, but several differences still ______ between them.

A. have　　 B. live　　 C. lay　　 D. exist

Obviously TV plays an important part in people's lives, for it brings us ____ images from around the worl.

A． casual　　　　 B． visual　　 C． gradual　　 D． spiritual

―Did they come to the biology laboratory ?（ ）

―I don't know. They _______ while I was out.

A. might have come　　　　　　　　　 B. might come

C. should have come　　　　　　　　　 D. must have come

Eco-travel is a form of travel ____ combines normal tourism with learning—a way to find out

　 what can be done to help animals, plants and people ____.

　 A. what; as well B. that; as well　　 C. that; as well　　 D. that; as well as

I went to bed very late last night, _____, early the next morning.

A. or rather              B. at least　　 C. at most                D. in a word

Only when your identity has been checked ____________.

A. you are allowed in　　　　　　　 B. you ’ll be allowed in

C. will you allow in　　　　　　　　 D. will you be allowed in