密码保存不注意，很可能吃大亏。

And if we're not careful about keeping them secret, they can cause big problems.

机械地照搬外国的东西要吃大亏的。

Mechanical copying of anything foreign would be disastrous.

我必须指明再延误就要吃大亏了。

I must point out that further delay will be unwise.