This artist made up his mind to devote all he could_____ his English before going abroad

题目

This artist made up his mind to devote all he could_____ his English before going abroad
improing 我不太理解

答案

首先
make up one's mind to do 固定词组,下定决心做什么
all是宾语,后面省略that,he could是定语从句,修饰all
to improving 表示目的.
to improving 固定词组,devote sth to doing