Réponse :
1. It's a hospital. You can't smoke
2.He had been working for more than 11 hours. He must be tired after such hard work.
3.My mum said we could eat this pizza if we want to. But we must leave it if we don't want to.
4. you can stand on your hands for more than a minute? No, I can't/couldn't
5.If you want to learn to speak English fluently, you have to work hard.
6. Take an umbrella. It will rain later.
7.People can walk on the grass.
8.Drivers must stop when the traffic lights are red.
9 Can I ask a question? Yes, of course. Can you speak Italian? No, I can't
10.
Explications :