The ________girl sat in the corner，________.
| A．frightening；crying |
| B．frightening；to cry |
| C．frightened；crying |
| D．frightened；to cry |
That was really a splendid evening party. It's years ________I enjoyed myself so much.
| A．when |
| B．that |
| C．before |
| D．since |
It is about 9∶30 pm. ________he comes back home after three evening classes.
| A．when |
| B．before |
| C．that |
| D．since |
It was in the lab _______was taken charge of by Professor Harris ________they did the experiment.
| A．which；that |
| B．that；what |
| C．whom；that |
| D．which；where |
________is it ________has made Peter ________he is today?
| A．What；that；that |
| B．That；that；what |
| C．What；what；that |
| D．What；that；what |
All workers in this factory are required to _______at the age of 60.
| A．resign |
| B．retire |
| C．restrain |
| D．retreat |