Ответ:

1. They were nervous because they had an exam.

They weren't nervous because they didn't have an exam.

2. She'd broughtt her camera so she took a photo.

She hadn't bring her camera so she didn't take a photo

3. We were amused because the film was funny.

We weren't amused because the film didn't be funny

4. I hadn't read the book so I didn't want to see the film.

I had read the book so I wanted to see the film.

5. He felt homesick because he was staying with an English family.

He didn't fell homesick because he wasn't staying with an English family.

6. You were feeling guilty because you'd made a mistake.

You weren't feeling guilty because you hadn't make a mistake.

7. We didn't go out because it was raining.

We went out because it wasn't raining