我们知道掌握一门外语并不容易。

We know that mastery of a foreign language is not easy.

youdao

世界各国的农民都知道掌握季节的重要行。

Farmers all over the world know the importance of the seasons.

youdao

鼠妈妈回过头来对孩子们说：“现在你们知道掌握一门外语的重要性了吧。”

"Now, you know the importance of a foreign language!" the mother said.

youdao

They really don't.So, if everybody masters the material A I can say A's on the house.

他们真的不知道，如果每个人都掌握了知识,那么我敢说，人人可得。

麻省理工公开课 - 固态化学导论课程节选

So it really, you know, becoming familiar with the different methods is best done through experience, not through books.

所以，真的，你知道，熟练掌握不同的方法最好是通过经验，而不是通过书。

迷上网页设计 - SpeakingMax英语口语达人

Anyway, the story ends and Nala goes back and is now armed with probability theory, we assume.

不管怎样,在故事结尾,那勒回去了,我们知道他已经掌握了概率论的知识

耶鲁公开课 - 金融市场课程节选