It was not until midnight __________ they reached the camp site.
| A．that | B．when |
| C．while | D．as |
The sun rises in the east and sets in the west，so it seems as if the sun__________round the earth.
| A．were circling | B．circles |
| C．is circling | D．be circling |
If you hadn’t taken such a long time to get dressed，we’d __________there by now.
| A．be | B．circles | C．is circling | D．be circling |
I apologize if I__________you，but I assure you it was unintentional(无意的).
| A．offend | B．had offended |
| C．should have offended | D．might have offended |
I would have gone to visit him in the hospital，had it been at all possible，but I __________fully occupied the whole of last week.
| A．were | B．had been | C．have been | D．was |
There is a real possibility that these animals could be frightened，__________a sudden loud noise.
| A．being there | B．should there be |
| C．there was | D．there having been |