14. My chief (usually work) on Saturdays. 15. He (wait) for you at this moment. 16. What your brother (do) for you at this moment? — He (be) a sportsman. 17. Ann is in the library. She (make) a report. 18. Recently, she (plant) some bulbs and flowers. 19. I (cook) a cake when he (come back) home yesterday. 20. Now Justin (write) a book about this adventure. I hope he can find a good publisher when it is finished.

1. My chief usually works on Saturdays.
2. He is waiting for you at this moment.
3. What is your brother doing for you at this moment? — He is a sportsman.
4. Ann is in the library. She is making a report.
5. Recently, she planted some bulbs and flowers.
6. I was cooking a cake when he came back home yesterday.
7. Now Justin is writing a book about this adventure. I hope he can find a good publisher when it is finished.

Использованы формы Present Simple для обычных действий и состояний, Present Continuous для действий сейчас, Past Simple для завершённых действий в прошлом и Past Continuous для действия, происходившего в определённый момент прошлого.