记住那个命令的键盘快捷键是值得的。

It's worth memorising the keyboard shortcut for that ___command.

一个常用的系统命令用于列出目录中的所有文件。

A common system ___command is used to list all files in a directory.

只有输入正确的命令，计算机才会响应。

The computer will only respond if you enter the correct ___command.