I'm rather used to having my toes trodden on by now,so I don't get upset.

问题描述:

I'm rather used to having my toes trodden on by now,so I don't get upset.
句子中这个ON如何理解啊?

践踏在了我的脚趾上
tread on my toes
被动后,on 也不能去掉.