Scientists say it may be five or six years ______ it is possible to test this medicine on human patients.
| A．before | B．after | C． since | D．when |
It is outer space might provide us with new energy sources.
| A．where | B．which | C．what | D．that |
If I enough money, I a DV before traveling.
| A．had ; would buy |
| B．had ; had bought |
| C．had had ; would have bought |
| D．would have ; would have bought |
——Didn’t you see Tom when he passed you?
——Sorry, I the kite in the sky.
| A．watched | B．was watching |
| C．had watched | D．have been watching |
When Fei Junlong and Nie Haisheng stepped out of the hall, all the cameras were on them, flashing quickly.
| A．pointed | B．aimed | C．focused | D．directed |
The athlete hurt his foot in the race.,he missed the champion.
| A．Consequently | B．Unfortunately |
| C．Potentially | D．Absolutely |