Exercise: may / might / must / can't

Choose the correct answer.

1. It ... can't must may be Sam. He's on holiday in Australia!
2. They are three hours late. They ... might can't must be lost.
3. Dad isn't here. He ... might can't must be at work but I'm not sure.
4. The phone is ringing. It ... must may can't be Sarah.
5. They ... must might can't be happy. Their team lost.
6. The cat isn't here. It ... can't might must be in the garden.