16. Let’s play a ........ now.

D. game

17. There ............ of stars in the sky.

C. are millions

Ns+ of stars.

18. My girlfriend is a ..........

A. gymnastic

Vì S+ be+ a/an+ adj.

19. My son is really afraid ......... dogs.

B. of 

CT: afraid of: sợ cái gì đó.

20. They want ........ to many different places in the country.

C. to travel 

Vì want+ to V.

16D. game

Câu BC thì số nhiều thì ko đúng vì có a nên ta chia ssos ít mà câu A thì guitar thì pghair dùng khi có V-ing

17C. are millions

There are+ N số nhiều+ of stars.

18A. gymnastic

S+ be+ a/an+ Adj.

19B. of 

be afraid of st: sợ cái gì đó.

20C. to travel 

Vì want+ to V: muốn cái gì đó