I am only able to look at nature through dirty curtains hanging before very dusty windows

题目

I am only able to look at nature through dirty curtains hanging before very dusty windows
请问为什么用hanging?
hanging是现在分词,表示主动,窗帘应该是被悬挂,不是应该用过去分词hung吗?

答案

表“悬挂”时,hang是不及物动词,无被动态.
我们只听说过sth.hangs(vi.) on the wall
没听说过sb.hang sth.on the wall吧.