a small fishing boat was carried miles out to sea by the powerful fish as it pulled on the line.

问题描述:

a small fishing boat was carried miles out to sea by the powerful fish as it pulled on the line.
as it pulled on the line,请问这是什么句,状语从句还是定语从句,怎么分析这个句子结构,和语法形式,请高手教我,
然后pull on 是词组吗,还是on the line是词组,怎么理解,

as it pulled on the line是时间状语从句.
1.a small fishing boat主语 was carried谓语动词 miles out to sea状语 by the powerful fish状语 as it pulled on the line.状语从句
2.as引导词 it主语 pulled谓语动词 on the line状语
pull on 不是词组,两个单词分别属于不同的意群
on the line是介词定语“对着钓鱼竿(拉pull)”