Відповідь:

1) You had lunch. You can't be hungry

2) She's wearing a wedding ring so she must be married.

3) The traffic pollution is very bad. There can't be many cars.

4) Jo isn't at home. He could be in town or at the beach.

5) She's crying. She can't be happy.

6) I can't find my keys. They could be in my bag or in my jacket.

7) He didn't answer. He can't be at home.

8) He could be a vet. I'm not sure.

9) You went to bed late. You could (must?) be tired.

Якщо відповіді неправильні, приношу свої вибачення. Дев'яте може мати два варіанти відповідей, але я гадаю, що "must" підходить більше.