She must have got ill.Otherwise She would have already been at work.
It must be more difficult than you supposed.
There's no light in the windows. There must be nobody at home again.
You have very many mistakes. You must pay more attention to grammar.
This question must be solved at once.
They must have been speaking about me. When I came up, they stopped talking at once.
She must be spending there a lot of time.
Nobody must be let in! Is it clear?
Children must be taught to swim as early as possible.
She must have known everything but she didn't want to upset me.