用must,mustn't,can,can't填空
1."___I come at 6 o'clock?""Oh no,you needn't."
2.A blind man___judge clours.
3."May I go there?""No,You___."
4.Two eyes___see more than one.
5.I___be off.Thank you very much for supper.
6.You___be careful.You___be careless.
7.___I stay up till midnight,please?
8.The teacher___favour some children more than others.