---Do you like the book I lent you yesterday?-Yes I do. I like books about sun.A. aB.

问题补充：

---Do you like the book I lent you yesterday?

---Yes, I do. I like books about sun.

A. a

B. the

C. /

D. an

答案：

A. a

(答案→)B. the

C. /

D. an

解析：定冠词the +世界上独一无二的物体前，比如earth，moon sun等前，故选B