Dưới đây là các câu hoàn chỉnh dựa vào cụm từ cho trước:

1. I must go to bed early tonight because I have a big day tomorrow.
2. Benny must work harder. He is going to fail his exams if he doesn't.
3. We needn't go shopping this afternoon because the fridge is full.
4. We needn't give Fran a big present; something small will be okay.
5. I'm going to tell you a secret, but you mustn't tell anyone!
6. You must cross the street at the pedestrian crossing to stay safe.
7. You needn't shout! I can hear you just fine.
8. You mustn't smoke in a restaurant in the UK. It's illegal.
9. You must do your homework on time, or you won't be prepared for class.
10. We mustn't forget Helen's birthday; it's next Tuesday.

Hy vọng các câu này giúp ích cho bạn!