A few grey hairs can be seen on her head.中on her head是主语补充语吧?还是定语?难倒是状语?

题目

A few grey hairs can be seen on her head.中on her head是主语补充语吧?还是定语?难倒是状语?
on her head是状语的话 感觉它没有修饰动作啊！你们是怎么判断的啊。我是这样想的：这句话是被动语态，on her head表明主语A few grey hairs 的位置，所以我认为是 主语补充语吧。

答案

是状语,介词短语作状语
可以把该句换成主动语态便于理We can see a few grey hairs on her head.