Don’t leave the water while you brush your teeth.
| A．run | B．running | C．being run | D．to run |
22. “How long do you suppose it is _______ he left for Japan?” “No more than half a month.”
| A．when | B．before | C．after | D．since |
21. Mr Zhang is mild in character. He never shouts ____ he is very angry.
| A．if | B．even | C．though | D．even when |
20. John shut everybody out of the kitchen _______ he could prepare his grand surprise for the party.
| A．which | B．when | C．so that | D．as if |
19. _______ rich one may be there is always something one wants.
| A．whatever | B．Whenever | C．however | D．Wherever |
18. _______ I can see, there is only one possible way to keep away from the danger.
| A．As long as | B．As far as | C．Just as | D．Even if |