求填入下题单词的适当形式,1.i saw him just now,so he ___[can not go]to sh

求填入下题单词的适当形式,
1.i saw him just now,so he ___[can not go]to shanghai.
2.listen!the boys____[must play]football on the play ground.
3.you'd better______[take]the doctor's advice.it's good for your health.
4.sorry,mr.li isn't here now.he____[go]to beijing.he_______[be]there for two days.
5.before i asked the price of the car,the owner_____[sell]it!what a pity!