Present Simple vs. Present Continuous

Вот ответы с использованием Present Simple или Present Continuous:

1. A: Why has he got his hand up?
   B: He wants the teacher to ask him.
   He knows the answer.
2. A: Why are you studying?
   B: I've got an exam tomorrow.
3. A: How do you prepare for exams?
   B: I read my notes and then I write questions for myself.
4. A: Who is singing downstairs?
   B: That's my sister. She's good, isn't she?
5. A: Bonjour, mademoiselle.
   B: Sorry, I don't speak French.
6. A: Mmmm. What's that smell? Is it pizza?
   B: Yes. My dad is making the dinner.
7. A: Why isn't your mum here at the moment?
   B: She finishes work late on Thursdays.
8. A: Can I speak to the director?
   B: No. He is speaking to someone else.