_____ had enough time, they would have visited the Great Wall。

A.pull out

B.run out

C.pick out

D.turn out

A.walking

B.to walk

C.walk

D.walked

A.as soon as

B.as long as

C.as far as

D.as much as

A.didn't keep

B.have not kept

C.don't keep

D.had not kept

A. man never made sounds

B. man made animal sounds

C. man used to be like animals to make sounds

D. man learned from the animals to make sounds

A. 150

B. 1,500

C. 5,000

D. ,000

A. To tell how "high tech" and "state of the art" have developed.

B. To give examples of "high tech".

C. To tell what "high tech" and "state of the art " are.

D. To describe very modem technology.

A. a microwave oven

B. a home computer

C. a hand pump

D. a satellite

A. Computer Technology

B. High Tech and State of the Art

C. Most Advanced Technology

D. Two New Expressions

A. are used to showing up for work

B. value unpaid work very much

C. are always opposed to unpaid work

D. could learn something about job security through unpaid work