（2012安徽卷）The limits of a person’s intelligence,generally speaking, are fixed at birth, but he reaches these limits will depend on his environment.
| A．where | B．whether | C． that | D． why |
Mr Wang went to Nanjing ____ October,1998 and came back home ____ the morning of Nov.5.
| A．at;in | B．on;at | C．in;on | D．by;from |
We have produced 15% more cotton this year____ we did last year.
| A．as | B．than | C．like | D．white |
The teacher is busy ____ correcting papers.
| A．for | B．in | C．on | D．of |
____ the problem of method is solved, talking about the task is useless.
| A．Until | B．Since | C．After | D．Unless |
Where have you been ____ you left home?
| A．before | B．as | C．since | D．when |