Choose the best options to complete the sentences

1. They
   [may|must] be away for the weekend but I'm not sure.
2. He
   [can|could] be French, judging by his accent.
3. You
   [can|might] be right but I'm going to check anyway.
4. Nobody is answering. They
   [could|must] be out.
5. He
   [can't|may] be from the USA. He doesn't speak English.
6. With luck, tomorrow
   [could|can't] be a sunny day.
7. The exam
   [can't|might] be easy. You never know.
8. She's been training 10 hours a day for three weeks. She
   [must|could] be tired.
9. She
   [can't|could] steal things from shops. She is rich and famous.
10. Dave reckons she's from the USA but I think she
    [can't|might] be from Scandinavia.