English modal verbs exercises

English modal verbs exercises. Choose the right modal verbs to complete the following sentences in English.

I'm not certain, but it _______ have been twenty to four.
1. might
2. must
You _______ have been sunbathing the whole week - you haven't got a suntan.
1. can't
2. must
Why don't you sit down? You ______ be exhausted after such a long journey.
1. must
2. may
It was very foolish of him to ran after the robber. He ______ have been killed.
1. could
2. can't
She ______ have gone on holiday. She's got too much work to do.
1. can't
2. must
It ________ have been Bob who left the lights on. He's always doing that.
1. must
2. can't
Bob _____ have tried to call earlier, but I don't know for sure.
1. may
2. can't
He _______ have picked up this knife because his fingerprints are all over it.
1. must
2. might
She _____ have eaten that whole bar of chocolate herself - it was very big!
1. can't
2. could
Tom ______ have been mad to do something like that.
1. must
2. may