——Mary stays alone in the classroom and looks sad.
——________ to her?
| A．What happens | B．What is happened |
| C．What is happening | D．What was happening |
—I didn’t see you at the beginning of the party last night．
—I________on nay biology report at that time．
| A．worked |
| B．work |
| C．was working |
| D．am working |
The girl was flying a kite________her father came back．
| A．when |
| B．while |
| C．until |
| D．after |
—I went to see you yesterday evening．But you weren’t in．Where were you then?
—I’m sorry．I________a walk by the lake with my classmates．
| A．am taking |
| B．was taking |
| C．take |
| D．took |
While we________about Mr.Wang in the classroom，he came in．
| A．talked |
| B．are talking |
| C．were talking |
| D．talk |
I was doing my homework________my father was reading newspapers．
A．how
B．while
C．if