______ I admit that there are problems, I don't agree that they cannot be solved.
| A．As | B．If | C．While | D．When |
A---It's a long time since I saw my sister.
---her this weekend?
| A． | Why not visit | B． | why not to visit |
| C． | Why not visiting | D． | Why don't visit |
The manager suggested an earlier date ____________ the meeting.
| A．on | B．for | C．about | D．with |
Some pre-school children go to a day care center, __________ they learn simple games and songs.
| A．then | B．there | C．while | D．where |
---Have you heard the latest news?
---No, What?
| A． | is it | B． | is there | C． | are they | D． | are those |
_____ in the queue for half an hour,Tom suddenly realized that he had left his wallet at home．
| A．To wait | B．Have waited |
| C．Having waited | D．To have waited |