"Tea is the world's second most popular drink, second to water, and there are literally thousands of tea formulations around the world, so the challenge for us, isn't finding new tea recipes, it's focusing and making sure we're developing things that are going to work."

VOA: standard.2010.02.17

But the challenge is that we really didn't have a business model at that time.

但问题是,那时公司没有一个商业模式。

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But you know, I understand it's a challenge when you're coming from a language that doesn't have any concept of an article.

但是，我能够理解当你的母语没有冠词的概念时，它将是一个挑战。

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Because it also means that every day we don't do something, we are not meeting a challenge.

因为这意味着,如果每天我们不去做些事情的话，我们所面临的挑战。

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Are you among those more comfortable, have you taken any computer science, were you programming at the age of 10 but you'd actually like to learn a bit about things you don't yet know and challenge yourself with new content or are you somewhere in between?

你对电脑比较熟悉么，你上过计算机专业方面的课程吗？,你是不是10岁就会编程,来上课的目的只是为了学习未知的知识,或者用新知识来挑战战自我？,还是二者兼有？

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And sometimes had them killed if he had to if he thought that's what he should do, because there wasn't any sort of challenge to his authority.

如果有必要,他甚至会杀掉那些碍事的议员,因为没有什么可以挑战他的权威

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There really can't be a challenge to them from the state itself.

绝对统治者不会允许在国内,有任何对于他们权威的挑战

耶鲁公开课 - 欧洲文明课程节选