-What are you going to do this Sunday?
-I ________ yet.
| A．won't decide | B．didn't decide | C．haven't decided | D．don't decide |
Most people are________building a paper factory near here．They are worried the river will get polluted．
| A．for |
| B．with |
| C．against |
| D．beyond |
Yesterday evening I was playing the piano________the doorbell rang．
A．when
B．before
C．while
Tony________TV when his mother came in．
| A．watch |
| B．watches |
| C．was watching |
| D．is watching |
I saw him in the library yesterday．He________a book at that moment．
| A．reads |
| B．is reading |
| C．was reading |
| D．will read |
（北京）—What were you doing when we were playing basketball yesterday afternoon?
—I________the classroom．
| A．was cleaning |
| B．have cleaned |
| C．will clean |
| D．clean |