Ответ:

  1. I write English exercises twice a week.
  2. My friend does his homework in the afternoon every day.
  3. My sister is doing her homework now.
  4. Don’t shout! The baby is sleeping.
  5. The baby always sleeps after dinner.
  6. What are you reading now?
  7. What books do you read at your literature lessons?
  8. What does your mother usually cook for lunch?
  9. Is she cooking a cake now?

Ответ: Present Simple употребляется для регулярных действий, а Present Continuous — для действий, происходящих сейчас.