Ответ:

  1. We visit our grandparents every Sunday.
  2. John is studying in his room at the moment.
  3. The lesson starts at 9 o'clock.
  4. She is thinking of painting her house.
  5. Are they leaving next week?
  6. What time do you start usually work?
  7. The flowers smell sweet.
  8. I don't think he is in.
  9. My mother is cooking lunch today, so please don't be late.
  10. Water does not boil at 80° C.