如果那时我们被发现了，我不知道我们会有什么后果。

If we had been spotted at that point, I don't know what would have happened to us.

《柯林斯英汉双解大词典》

如果你不知道自己的胆固醇水平，最好去查一下。

If you don't know your cholesterol level, it's a good idea to have it checked.

《柯林斯英汉双解大词典》

如果你不知道什么是鹰头狮，请看图片。

If you don't know what a Gryphon is, look at the picture.

youdao

- "She lived unknown and few could know"-- how can she be unknown if few know anything about her?

她不为人知地活着，鲜有人知道她“,如果有任何人知道关于她的任何事情,又怎么能说他不为人知呢？

耶鲁公开课 - 文学理论导论课程节选

It's very exciting, but if you think you know everything you don't need to learn, you don't belong to us. I always need to learn.

这很令人兴奋，但如果你认为,你什么知道，你不需要学习了，那么请你退出百度，因为人总是在学习。

斯坦福公开课 - 百度CEO李彦宏演讲：全球最大搜索引擎的发展课程节选

If you don't know why you're about to eat cake like that you will soon, but you know this.

如果你现在还不知道为什么将要吃到那样的蛋糕,很快就会知道的，你清楚这一点。

哈佛公开课 - 计算机科学课程节选