Look at the picture and choose the correct options

1. I don't believe your words! It
   [must|might|can't]be true!
2. Where's my mobile? It [could|can't|must] be in my bag, but I'm not sure.
3. You
   [can't|might|must] be joking! That's cool news!
4. She [must|might|can't] already be at home. It's 6 p.m., and she usually comes at 5.
5. I doubt where Sam is. I think he
   [can't|may|must] be at his friend's house.
6. This dress
   [can't|might|must] be so expensive! There's a sale sign on it.
7. I don't know if he's telling the truth. He [can't|must|might] lie to you.