— What do you think of the book?
— Oh, excellent. It is worth ________ a second time.
| A．to read | B．to be read |
| C．reading | D．being read |
Stop smoking, ________ your health will get worse soon.
| A．and | B．or | C．but | D．s o |
________ dog is ________ useful animal and ________ honest friend as well.
| A．A; a; an | B．A; an; a | C．The; an; a | D．The; an; an |
The garbage too much space .
A. takes away B.takes off C. takes up
We should do everything we can the environment .
A. to protect B. protectC. protecting
______of the earth ______ covered by water.
A. Two thirds; is B. Two thirds; are C. One thirds; is