简单的英语语法问题

doing chores around the house在定语从句中做方式状语。

结构分析：
1. 主句：The couple of bucks was never going to be enought to buy comics or model plances.
2.主句主语the couple of bucks被其后的定语从句I earned doing chores around the house所修饰。
其中，被省略的关系代词which/that等同于先行词the couple of bucks，在定语从句中充当earned的宾语。
即定语从句变化为：
(which/that) I earned doing chores around the house
= I earned which/that doing chores around the house
= I earned the couple of bucks doing chores around the house

定语。
用来修饰主语

主干是：The couple of bucks was never going to be enough to buy comics or model planes.
I earned 是定语从句，即这几美元是我赚来的几美元
doing chores around the house是方式状语，即“我赚”是通过“给别人做家务”赚来的