．Days of snowstorms have left the city under thick layers of ice and some 50,000 homes without power．
| A．to be trapped | B．trapped |
| C．having trapped | D．being trapped |
. The government has _______ the parents to work with teachers in the education of their children.
| A．asked for | B．called for | C．looked for | D．paid for |
. The plan ___ just because people were unwilling to co-operate（合作）。
| A．broke down | B．pulled down | C．turned down | D．put down |
. My study of biology has ___C___ much of my spare time， but it has given me a great deal of enjoyment.
| A．taken off | B．taken down | C．taken up | D．taken away |
. Elephants would ______ if men were allowed to shoot as many as they wished.
| A．die down | B．die out | C．die away | D．die off |
. I had to ______ because someone else wanted to use the phone.
| A．give up | B．put up | C．hang up | D．ring up |