this is a book _____ which I spend 5 yuan.

问题描述:

this is a book _____ which I spend 5 yuan.

On,spend...on sth.

填 in ,spend sth in sth

on
spend...on...在……上花费……

这是一个定语从句,介词短语前置,spend...on...在……上花费…… 所以这里填on