I.Modal verbs: can,may,must 1.May be she will return tonight- she... Return tonight 2. Don't stand up!-you... Stand up 3. I'm sure they will finish it in a minute. They .... finish it in a minute 4.there is no need to answer the letter.you..answer thể letter 5.please do it for me- ...you do it for me 6. I'd like to see your children-...i see your children 7.i am not good at football-i....play football 8.do your homework!-you...do you homework 9.let's take a taxi-we...take taxi II.choose have to, don't have to,can,can't, should, shouldn't, 1.you....shout at the children. It frightens thêm 2.im sorry but you ...bring your dog in here. It's forbidden 3. You...have a visa before travelling to the usa. It's the law 4. You...stay in the library till eight o'clock. It's open all evening 5.i think you..think carefully before you sell the house 6.you...buy a new alarm clock. This one is broken 7.you ....wear a uniform at my new school 8.you... leave your bag open on the bus 9.we...go now or we'll be late 10.she... dance very well but she can't sing 11.you...be at the airport by five o'clock