The other quick thing I want to say is that I do have office hours today from 3 to 5, so feel free to stop by if you have questions about problem-set 3 that you're finishing up.

我还想说一件小事,我今天的答疑时间是三点到五点，如果你对于第三次作业还有任何疑问,请在这个时间段来找我，不必客气。

麻省理工公开课 - 化学原理课程节选

But it's not a big con, because you can set up experiments in free space far from everything, where objects will, in fact, maintain their velocity forever.

但这并不是个反例,因为你可以在一个远离一切的空间里做实验,在那里,物体可以永远保持现有速度

耶鲁公开课 - 基础物理课程节选

scratch Scratch is a program that you can download for free cs50 net and you will see in problem set 0 0 which will be posted on CS50.nettonight under problem sets in both standard and hacker editions, can you do the--can you--it will walk you through the process of getting this software.

你可以免费下载,今天晚上我会在0,放上习套题,这个习题集有两个版本，习题集可以指导你,如何下载这个软件。

哈佛公开课 - 计算机科学课程节选

I mentioned something of increasing importance only later, which is that you are free to pick another set of axes, not in the traditional x and y direction, but as an oblique direction.

后来我又讲了更重要的知识点,你可以随意选取另外一个坐标系,不再是传统的 x 和 y 方向,而是倾斜过的方向

耶鲁公开课 - 基础物理课程节选