—Your watch is so beautiful. It must be expensive.—Not at all. I only ￥20 on it. A. cost B

问题补充：

—Your watch is so beautiful. It must be expensive.

—Not at all. I only ￥20 on it.

A. cost B. spent C. paid

答案：

解析：根据几个动词的用法，cost的主语为物，spent 与paid的主语为sb，其结构为sb+spent money +on sth。故选B