---I think you can money by yourself to buy a birthday present for your mother---OK. I

问题补充：

---I think you can money by yourself to buy a birthday present for your mother.

---OK. I’ll try. I’ll not let a penny waste.

A. spend

B. save

C. cost

D. leave

答案：

A. spend

(答案→)B. save

C. cost

D. leave

解析：B 由“我不会浪费一美分的”知，上文讲的是“省钱”，故选B。