Who left their laptop on my desk? It [mustn't/can't] _____ (be) Mel's – she's working at home today.

He [may not/can't] _____ (be) our teacher! He looks about twelve!

Take this umbrella just in case. It looks as if it [might/can] _____ (rain).

It is still a mystery how the robber gained access to the bank. Police are investigating whether the suspect [must/may] _____ (know) one of the employees.

Do you remember my birthday party last year? You [can't/must]  _____ (remember)! It was the same day as your graduation.

The exam results will be out soon. It [must/might] _____ (be) this week or possibly next week.

She always gets such good grades at school. She [might/must] _____ (work) very hard.

The doctor said my headaches [could/must]  _____ (be) because of the hot weather but they're going to do some tests to be sure.

Come in and sit down. You [could/must] _____ (be) tired after the journey.

Oh no! My phone's not in my bag. I [could/must] _____ (leave) it at home.

Whose is this coat? It [can't/mustn't] _____ (be) Paul's. It's way too small for him.

She [might not/can't] _____ (clean) the whole house on her own in two hours. She must have had some help.

Why were there no buses yesterday? Maybe it was the snow or they [might/must]  _____ (be) on strike.