Scientists say it may be five or six years _______ it is possible to test this medicine on human patients.
| A．since | B．after |
| C．before | D．when |
I shall take you to France ________ you are well enough to travel.
| A．quickly | B．directly | C．finally | D．happily |
—He should have come to join in the thorough cleaning.
—He ________, I think. It's not his turn.
| A．needn't have to | B．needn't have | C．didn't have to | D．doesn't need to |
Fisherman Wang Bingzhong from Changli county,Herbei province,examines his boat on May 25 after it was damaged in ________he described as a pirate attack.
| A．which | B．that | C．what | D．where |
The enemy troop could hardly make any advance, and ________ could they fall back.
| A．neither | B．so | C．either | D．both |
You can’t imagine the hard time he had ______ the horse in.
| A．holding | B．to hold | C．held | D．hold |