Chia động từ khuyết thiếu
1 What's in the box ? - It might (be) a ball
2 What can I (do) for you ?
3 May I (come) in ?
4 What should we(do) now ? 
5 Children should (not watch) TV much
6 You must (not cross) the road alone 
7 Students ought (not eat) fast food everyday.
8 When I (be) small , I (can/play) the guitar
9 Yesterday , I (have to) (take) him to the hospital because he (be) ill
10 Are you able to (speak) French ?