Modals

[Can/Must] I leave now? I need to get home early today.

Richard still hasn't arrived.Do you think I [should/must] call him?

You [shouldn't/mustn't] make any noise in the library - people are reading and studying.

[Can/ Are] you allowed to take photos in the museum?

You [have to/ don't need to] study hard if you want to become a doctor.

You [mustn't/ don't have to] go to classes to learn English, but it's more fun.