1 C

-> ta có cụm từ : in your / his / her spare time / free time

2 D

-> go + to V

3C

-> ta có cụm từ take photoes 

4D

-> thì HTĐ : s + vs/es

-> dấu hiệu : sometimes

5B

-> V + adj

6A

-> ta có cụm từ have a good time

7D

-> cấu trúc keen on doing something

8B

-> spend + time

B

1 stamp collection is an interesting hobby

-> vật + adj + V-ing

2 you can learn many things such as the geography of a country from stamps

-> can + V nguyên mẫu

3 poster stamps are a source of interesting facts and important dates about every country in the world

-> N số nhìu + are 

4 it makes stamp collecting become very popular

-> very + adj

5 as you look at the pages of a stamp album, you can learn interesting details of foreign customs  arts  literature  history and culture

-> cấu trúc look at the + N + of a / an + N

6 their colors can make you feel relaxed and happy

-> cấu trúc make sombody + V nguyên mẫu

7 collection stamps can become a business