1) This is not right of you.

这件事你不公道。
2) No blame attaches to you in this affair

这件事不怪你.
3) You must never do this.

这件事你做不得。
4) The matter is in your hands.

这件事由你负责。
5) This is up to you.

这件事取决于你。
6) I'm quite in the dark about it.

这事我不知道。
参考词条