Ⅰ.用适当的情态动词填空
1．He won't be able to come again tomorrow because he is very busy.
2．You can't smoke here.Go out of the house if you must．
3．He broke his leg and had to lie all the time.
4．She could play several instruments at the age of eight.
5．We had better leave now or we'll miss the bus.
6．Tony has known the good news，so you need not tell it to him.
7．Parents are doing all they can to help their children achieve their ambitions.
8．As he was seriously ill，he had to stay in hospital.
9．He dare not do it because he is very afraid.
10．He can not be attending the meeting now because he has gone to Beijing on business.
