---If there are ______ people driving , there will be ______ air pollution.--- Yes, the air will be fresher.
Mum often ________ us not to play in the street.
Don’t read ________the sun. It’s bad for your eyes.
If you are tired, you can ________ a rest.
The school has eight _______ students.
-----I have to go now. -----It is raining . Don’ t ______ until(直到) the rain stops.