1. My hands are tied 我无能为力

A: Mr. Chapman, can I hand in my homework next time. I left it at home. Chapman 先生，我能不能下次再交作业呢？我把功课忘在家里了。

B: All of the scores¹ must be given² to the office by Friday, so you must have your homework today. It is a school rule and there is nothing I can do. My hands are tied. 所有的分数都必须在礼拜五前交到办公室(学校)，所以你今天一定要有你的作业。这是学校的规定，我无能为力。

"My hands are tied." 在这里并不是真正"手被绑起来"的意思，而是指"没办法"的意思。好比电话响了，你很忙不能接，也可以说"Can you get it? My hands are tied." (我很忙，你能接一下吗?" )

2.There's nothing I can do about it. 这事我一点办法都没有/我也无能为力.

I understand how you feel, but I'm afraid there's nothing I can do about it.

我理解你的心情,但恐怕我也无能为力.