Ответ:

4)are they doing

5)are dancing

6)Are Mum and Dad dancing

7) is

8)isn't

9)is talking

10)are laughing

11)is

12)is dancing

13)is giving

14)are they drinking

15)are drinking

16)isn't drinking

17)Are they eating

18)aren't eating

19)are sleeping

20)are looking

21)is coming