If it hadn't been for him, we would have gone astray.

　　如果不是他的話，我們就迷路了。

　　An error, the breadth of a single hair, can lead you a thousand li astray.

　　差之毫厘，謬以千里。

　　A lamb goes astray on a forked road.

　　歧路亡羊。

　　In the present instance, you are quite astray.

　　這樁事上你可完全搞錯啦！

　　How can we sit idly by and watch him go astray?

　　咱們哪能眼看著他走邪道不管呢？