() 10. Jack bought useful book. book is also very interesting.

A.an; The
B.a; The
C.an; A
D.a; A

B

第一空表示泛指，有用的一本书，useful以辅音音素开头，因此用a修饰。第二空指代前文提到的那本书，用定冠词the表示特指。

Ⅱ. Fill in the blanks with a, an, the or /.
1. Tomorrow is Children’s Day and we’ll go boating in a park.
2. We often go to cinema at weekends.
3. I am interested in English.
4. There is house in the picture. And there is old woman near house.
5. Last night I went to bed very late because of too much homework.

1. /
2. the
3. /
4. a, an, the
5. /

1. Children's Day是节日，节日前一般不用冠词，所以此处不填。
2. “go to the cinema”是固定短语，表示去看电影，所以用“the”。
3. “be interested in”后接名词，“English”作为语言，这里表示对英语这门学科感兴趣，不用冠词。
4. “house”是可数名词单数，且此处是第一次提到，用不定冠词“a”；“old”是以元音音素开头的单词，所以用“an”；第二次提到前面的“house”，用定冠词“the”。
5. “go to bed”是固定短语，意为上床睡觉，不用冠词。

Ⅲ. Translation.
1. 弹钢琴
2. 弹吉他
3. 拉小提琴
4. 吹笛子
5. 打鼓
6. 打篮球
7. 打排球
8. 踢足球
9. 打网球
10. 打乒乓球
11. 打羽毛球
12. 下象棋
13. 年轻人
14. 布朗一家人
15. 戴着眼镜的男孩
16. 短发的女孩
17. 穿着紫色套装的男士
18. 穿着红色连衣裙的女士
19. 课桌上的书本
20. 我家附近的工厂

1. play the piano
2. play the guitar
3. play the violin
4. play the flute
5. play the drums
6. play basketball
7. play volleyball
8. play football
9. play tennis
10. play table tennis / play ping-pong
11. play badminton
12. play chess
13. young people / young men (young 也可单独使用表示年轻人，但people更完整)
14. the Browns / the Brown family
15. the boy with glasses
16. the girl with short hair
17. the man in a purple suit
18. the lady in a red dress
19. the books on the desk
20. the factory near my home