The students can’t go home________they finish cleaning the classroom,for it’s their duty.
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.
I have a new ______ . I can put my money in it.
Water is very dangerous sometimes. So we must be careful _____ it.