When you finish reading the book you will have better understanding of life.A. a；theB.

问题补充：

When you finish reading the book, you will have better understanding of life.

A. a；the

B. the；a 

C. /；the

D. a；/

答案：

A. a；the

B. the；a 

C. /；the

(答案→)D. a；/

解析：understanding前有形容词修饰时可与a连用；life统指“生活” 时是不可数名词。