We were just about to call him ________his mother came back.
| A．while |
| B．as |
| C．when |
| D．because |
I'm busy now. I'm sorry I can't help ____ the flowers.
| A．watering | B．watered | C．waters | D．to water |
In New Zealand, I made lots of friends ___ a very practical knowledge of the English language.
| A．get | B．to get | C．getting | D．got |
He will tell you _____ he expects will win such a match.
| A．why | B．whom | C．which | D．who |
We should do more such exercises in the future, I think, _____ those we did yesterday.
| A．as | B．like | C．about | D．than |
The professor has written another book ____ of great importance to computer science.
| A．which I think it is | B．and I think is |
| C．which I think is | D．when I think is |