_____ all the demands had been refused _____ to go on strike.
| A．Only; did the workers decide | B．Not until; the workers decided |
| C．Not until; did the workers decide | D．Only after; the workers decided |
There is such a problem _________ we all should _________.
| A．as; pay attention to it | B．that; attract our attention |
| C．as; pay attention to | D．that; attract our attention to it |
In the competition to be held, a gold medal, together with a certain sum of money, _________ the champion.
| A．will be given to anyone who will win |
| B．will be given to whoever will become |
| C．has been given to whoever wins |
| D．was given to anyone who became |
You will have to wait for one more week, _________ the manager will be back from his trip.
| A．when | B．before | C．as | D．until |
_________ environmental damage is done, it takes many years for the ecosystem to recover.
| A．Even if | B．If only | C．While | D．Once |
After he became conscious, he remembered _________ and _________ on the head with a rod.
| A．to attack; hit | B．to be attacked; to be hit |
| C．attacking; be hit | D．having been attacked; hit |