题目内容：

If you make a mistake once,it's not the end of the world---just don't make the same mistake twice

优质解答

OK let me translate it
If you make a mistake once:如果你犯了一次错误
it's not the end of the world:这还不是世界末日
just don't make the same mistake twice:只是不要犯两次同样的错误.