-What do you think of the book?
-Oh, excellent. It is worth _____ second time.
| A．to read a | B．to read the | C．reading a | D．being read the |
In September 2008,China’s key milestone in space travel _____when Zhai Zhigang
conducted the first space walk.
| A．reached | B．was reached |
| C．has reached | D．had been reached |
We _____ last night,but we went to appreciate the flowerbeds and streetlights in Tian’anmen Square instead.
| A．might study | B．could study |
| C．should have studied | D．must have studied |
Each of us, ____old or young,is a valuable member of society.
| A．however | B．whenever |
| C．whoever | D．whatever |
If a computer crashes,you will lose the file you _____ on unless you save it regularly.
| A．are working | B．work |
| C．will work | D．worked |
There you can see beautiful tall buildings on _____side of the square.
| A．all | B．either | C．both | D．every |