内核用页描述符来确保能找到所有的页，每个页都有相应的页描述符，页描述符里存放这页状态的有关信息。

A kernel USES page descriptors to keep track of all physical pages. Each page frame has a corresponding page descriptor. In a page descriptor the information about state of page is stored.

youdao

定义为nsd的磁盘的磁盘描述符包含在一个文件里，- F标志就用来指向这个文件。

The -f flag is used to point to a file containing disk descriptors for disks to be defined as NSDs.

youdao

我希望这些能够充分的解释连接操作符的基本概念和在PHP里的作用，以及我对这个基本操作的经验。

I hope this sufficiently explains concatenation in general, how it relates to PHP, and my experience with using this basic operator.

youdao

When I try and evaluate that expression of greater than, is going to go into the class to say greater than is a comp method.

这个大于的操作符的时候,是到类的定义里去识别，大于是一个比较的方法,那么让我在这里说仔细一点吧。

麻省理工公开课 - 计算机科学及编程导论课程节选

And I don't quite remember from reading or from class how big these things are, well, it turns out -- and this is sometimes useful, later on more likely than now -- but C has a size of operator that takes an argument in parenthesis and it will tell you how much space is used to store that particular data type.

我不太记得类中的这些类型,是多大的，嗯，结果是--这个在以后比现在，可能是更有用的--不过C语言中有个sizeof的操作符,其中括号里有一个参数,它会告诉我们，要存储一个类型的数据,需要占用多大空间。

哈佛公开课 - 计算机科学课程节选