The World Expo 2010 is being held at a time the world is looking for a new kind of balance between nature and cities．
| A．when | B．where | C．which | D．that |
25. “I’m going to the post office.” “_______ you’re there, can you get me some stamps?”
| A．As | B．While | C．Because | D．If |
24. “May I go and play with Dick this afternoon, Mum?” “No, you can’t go out _______ your work is being done.”
| A．before | B．until | C．as | D．the moment |
23. In some countries, _______ are called “public schools” are not owned by the state.
| A．that | B．which | C．as | D．what |
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 |