1. He gets good marks.

2. She doesn't want him to get ill.

3. She thinks it's not good and people should study with others sometimes.

4. She tries to be positive and she imagines that she passes an exam.

5. Because he's stressed and worried that if he doesn't revise every day, then he won't pass his exams.

6. He will do it because she decided that he's going out with her that night.