The weather is bad. You shouldn’t risk _______ mountains.
| A．to climb | B．for climb |
| C．for climbing | D．climbing |
—How many students are there in the classroom?
—_____. I don’t know where they have gone.
| A．No one. | B．None. | C．Nobody. | D．Nothing. |
The rubbish _____ is produced every day is becoming a serious problem in cities around the world.
| A．that | B．who | C．where | D．whom |
More and more trees were cut down. _____, many animals are dying out.
| A．In the end | B．So that |
| C．As a result | D．At last |
We should often keep _____ touch with each other, because we are good friends.
| A．on | B．to | C．in | D．up |
—What do you think this coat is made _____?
—Wool. It’s used for _____.
| A．of, keeping warm | B．from, keeping warm |
| C．in, keeping warmly | D．of, keeping warmly |