When you want to know if something is transparent to visible light or not, here is the mystery material and here is visible light.

当你想知道某物对可见光是否透明时，这里是神秘物质，这里是可见光。

youdao

When they get to know me and to trust me, knowing for sure I'm not selling them something—there'll be more honest feedback from them.

当他们开始了解我、信任我，并确信我不是在卖什么东西给他们时，他们会给出更诚实的反馈。

youdao

If you wouldn't want your class to know or see something, you shouldn't share it with anyone online, not even your best friends.

如果有些事情你不想让同学知道或是看到，你就不该在网上跟任何人哪怕是最好的朋友来分享。

youdao

There something happens. He does not know how, but he has been transported to the Red Planet,Mars.

VOA: special.2010.07.17

The problem is, I want to know if, in fact, I've got something that's not of the form I expect.

问题是,我希望知道如果输入的。

麻省理工公开课 - 计算机科学及编程导论课程节选

Or perhaps, you could be trying to explain that you don't know whether you can do something or not by a certain date.

又或者，你正在试图解释你没法确定你是否能在一个指定日期前做完某件事。

I don't know 课堂 - SpeakingMax英语口语达人

You may not know what you need to know until you try something.

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They were close enough to the crash site to know that something unusual had happened but far enough away to not know what it was.

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But, "when you don't know the answer, refer them to someone who does and know when it's not our place to say something, " says Ms. FitzPatrick.

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