The volunteers try to convince people _____ the fact that some species are in danger of _____.
| A．for; dying away | B．about; dying down |
| C．of; dying out | D．on; dying off |
On Christmas Day, children have _____ singing, dancing and playing games.
| A．funs | B．a fun | C．the fun | D．fun |
The report indicates that the new power station produces energy as the one built earlier.
| A．twice as much | B．as twice | C．twice much as | D．twice much |
So far there is no proof people from other planets do exist.
| A．how | B．what | C．which | D．that |
_____ scores of times , but he still couldn’t understand it ．
| A．Having explained | B．Having been explained |
| C．Though it was explained | D．It was explained |
________ their son away to college, the old couple got more room in the house．
| A．As | B．For | C．Through | D．With |