请翻译: 既然知道这个事情,还来问我干什么?

既然知道这个事情,还来问我干什么?
Since you already knew, why bother to ask me again?

楼上的是机器译的吧？
Why do you ask me this since you know it well?

Since you've known the matters,leave it out !(省略它）也就是不要再问了！

Since knows this matter, but also asked what I do do?

Since you have known this matter, what is the point of asking me?