选择合适的情态动词填空（should,may,can,must)

选择合适的情态动词填空（should,may,can,must)
1.It is raining outside.You _____stay here a little longer
2.It ____not be Jerry.He flew to London this afternoon
3.Visitors_______not walk on the grass in the park
4.You _____not tell my mum the bad news
5.Look into your desk.Your keys_____be in it
6.The little boy ____speak English and a little Japanese
7.Mum,_____I watch TV after I finish the homework?

1.should
2.can
3.must
4.may
5.may
6.can
7.may