分析子成分 The doctor did his best to do what he could to help the sick boy .主要说明 he could 是什么成分
问题描述：
分析子成分 The doctor did his best to do what he could to help the sick boy .
主要说明 he could 是什么成分
答
the doctor 主语
did 谓语
his best 谓语补足语
to do what he could to help the sick boy 宾语
答
The doctor是主语
do one's best 是竭尽所能；尽力，尽自己最大努力
to do 是状语吧
答
the doctor是主语,did是谓语.后面是一个有what引导的宾语从句,整个句子做宾语.宾语从句里he做主语,could为谓语,what引导词做宾语.