If you feel exposed without a text book, you really have to have a textbook, John actually I'm going to reuse that word, John, at least suggest it, on the course website.

如果你觉得没有教科书就缺乏安全感的话，那你真的需要一个了，其实我应该重新使用这个词儿，至少是建议，你能在课程网站上找到。

麻省理工公开课 - 计算机科学及编程导论课程节选

If the vehicle in the unfortunate circumstances of a collision, has to be able to maintain the security of the hydrogen which means more mass, which means a lot of the efficiency is being squandered What's the environmental impact of hydrogen production?

如果车辆,在碰撞中发生了不幸，要仍然能够保持氢气的安全性的话,意味着需要更多的质量，也就是说大部分效率被浪费了,制氢对环境有什么影响呢？

麻省理工公开课 - 固态化学导论课程节选

The personal aid isn't a National Security offical but a person always knows what the president's schedule is, has his briefing book, his speech, his man, whatever the president needs to just keep functioning.

私人助理不是国家安全部官员,但是他必须知道,总统的行程如何，拿着他的简报，他的发言，他的人手安排，一切总统维持正常工作,所需要的东西。

普林斯顿公开课 - 国际座谈会课程节选

I think that part is fine, but behind that you need something to replace what was there When you have peace then you need to bring in stablity that means economic stability as well as security stability You need the police. You need the government. You need the economy.

我认为计划本身是好的，但还需要一些东西来填充以为以前的空缺,和平了，你就需要稳定，经济稳定，安全局势的稳定等,我们需要警察，需要政府，经济也要发展。

普林斯顿公开课 - 国际座谈会课程节选