The air pressure in a plane during flight is lower than at sea level.

VOA: special.2009.07.14

But as part of a more rigorous introduction to understanding how the machines work and writing programs at this lower level.

作为一种,理解电脑工作机制,和在低平台上编程的入门方法。

哈佛公开课 - 计算机科学课程节选

But it turns out that with this language we glimpsed on Wednesday, you can do the step so much more easily and yet the ideas are identical to what we're gonna explore at a lower level in the weeks to come.

实际上，通过在周三,学习的Scratch语言，你可以更容易地做这步,思路和今后几个星期,我们将探讨的是相同的。

哈佛公开课 - 计算机科学课程节选