If you just scramble a sentence, it's pretty useless because the recipients are never going to be able to reverse the process.

如果你只是加密一个句子，这是毫无用处的,因为收件人没法将这个句子,反加密出来。

哈佛公开课 - 计算机科学课程节选

The reason that it seems difficult to say though is because it seems like it would be just as plausible to say the reverse.

但真的要说出来似乎有困难,因为反过来说也貌似合理。

耶鲁公开课 - 死亡课程节选

Cmp is just saying, cmp and if I want to reverse it, it goes the other way.

一个比较的方法了，的意思是，是不是大于，is，this，bigger，than，如果我反转了参数的顺序，它的意思就是是不是小于了。

麻省理工公开课 - 计算机科学及编程导论课程节选