Scientists say it may be five or ten years___________ it is possible to test this medicine on human patients.
| A．since | B．before | C．after | D．when |
Though David talked about the origins of ______ universe, I didn’t think what he said made ______ sense.
| A．the; / | B．the; a |
| C．/; / | D．/; a |
Our plan to ______ a New Year’s party has won supports from our teachers.
| A．organise | B．volunteer |
| C．solve | D．invite |
—Bob has gone to California.
—Oh, can you tell me when he ______?
| A．has left | B．left |
| C．is leaving | D．would leave |
Leave your key with a neighbor _____you lock yourself out one day.
| A．ever since | B．even if |
| C．soon after | D．in case |
It was two weeks before the Spring Festival and the shopping centre was _____ with shoppers.
| A．full | B．crowded |
| C．satisfied | D．noisy |