1 A: I'm not feeling well again.
B: You MUST stop working such long hours on your computer.
2 A: Jane is doing her homework. You MUSTN'T shout.
B: OK.
3 A: You MUSTN'T tell anyone. It's a secret.
B: OK, I promise.
4 A: I've got a headache!
B: Well, you MUST stop texting so much.
5 A: Can I play video games, Mum?
B: Of course, but first you MUST help me with the chores.