Ответ:

1. When did Tom start playing the piano? (start/ Tom) 1) At 8 30. 2) In 1999. 6) When he was 6. (все три возможны)

2. When did he finish university? (finish/ he) 2) In 1999.

3. Why did Sam eat this apple? (eat/ Sam) 9) It is tasty.