Fill in: must, can't or may.
1 That man over there can't be Tom. He's abroad at the moment.
2 Helen may have called earlier. I'm not really sure.
3 Jane's not online, so she must have turned off her computer.
4 Kate can't have been chatting online. She doesn't even have the Internet!
5 Steve must be watching a film now. I'm sure of it!
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llevell