你可以使用人行道，它是安全的。

You can use the sidewalk. It's safe.

youdao

一个关键因素是土地的安全使用。

One crucial factor is secure access to land.

youdao

这家航空公司有几架飞机暂时不能使用，正在接受安全检查。

Several of the airline's planes are temporarily out of commission and undergoing safety checks.

《牛津词典》

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

But in society today, and we'll talk a bit about security topics -- and such throughout the course, for cryptography -- for encrypting things like your credit card information and bank accounts -- you don't use 32 bits, you don't use 64 bits, you generally use 1024 bits, 4,048 bits.

但在当今的社会上，我们将讨论一点安全方面的知识,贯穿整个课程，密码学-,加密一些像信用卡信息,银行账号之类的东西--你不能用32位，你也不能用64位，你通常要使用1024位，4048位。

哈佛公开课 - 计算机科学课程节选

But the point is that how is Facebook, how is Amazon possibly going to communicate securely with you or your laptop using cryptology if you both have to know the same secrets.

关键是Facebook是怎么样，亚马逊是怎么样安全地和你或你的计算机,使用加密技术进行交流的，如果你们两个都,知道那个同样的密钥。

哈佛公开课 - 计算机科学课程节选