Be on your guard.

你要提防着点儿。

Our competitor has a better product. There's no denying it.

无可否认，我们的竞争对手拥有更好的产品。

Let it be.

随它去。

I'm sorry to say this, but there seems to be a mistake.

对不起，这儿好像有个错。

This all boils down to what?

煮到最后剩下……意味着， 表明是

I needed that like a hole in the head.

简直想要了我的命。