我看不出那个计划背后的逻辑。

I don't see the ___logic behind that plan.

如果我们运用一些逻辑，就能解决这个问题。

We'll be able to work this out if we use some ___logic.

在那上面花这么多钱毫无道理。

There's no ___logic in spending so much on that.