Ответ:

  1. He is singing.
  2. She is reading a book.
  3. Tom is jumping.
  4. They are riding a bike in the garden.
  5. We are making a snowman.
  6. I am cooking.
  7. Martin is playing the guitar.

Время Present Continuous образуется с помощью am/is/are и глагола с окончанием -ing.