And ultraviolet light will interact with that little ball, the center of mass, and when I then make it dark, you will only see the motion of the center of mass.

这紫外线光可以，与小球互动，也就是质量重心，当周围暗下来，能看到质量重心运动。

youdao

No more do I have to make myself lower than you, and become your fan to interact with your page, I just have to like it.

上你的主页时，我再也不需要让自己低你一等并且成为你的粉丝，我只要随我的喜欢就行了。

youdao

There’s a lot more to this topic than I can cover in a short paragraph, but the objective of here is to make it as easy as you can for the user to navigate and interact with the website.

我不能用一小段文字表达这个话题，因为这个话题包含了太多内容。 但我想说的是，让你的网站尽可能地变得简洁，让用户可以更轻松地浏览网站，进行网站活动。

youdao

And I know that many of you have had a chance to interact with our Secretary of Education, Arne Duncan, who's doing a terrific job, and I think you understand when you talk to him that this administration is serious about breaking down some of the barriers to reform that have existed in the past.

WHITEHOUSE: President Obama Calls for New Steps to Prepare Children for College and Careers | The White House