I believe the declaration that "all men are created equal" is the great fundamental principle upon which our free institutions rest;
VOA: special.2009.02.09
And fairly soon into the conversation I demonstrated some principle that you've probably learned in your physics class having to do with an object at rest remaining at rest unless acted upon by a force.
很快,在交谈中,我就展示了一些原理,可能你们在物理课上学过,要使静止的物体保持静止,必须有外力作用。
What makes the law surprising is that if I only gave you half the law, namely every body will remain at rest if it's not acted upon by a force, you will say, "That's fine. I accept that, because here's something, you leave it there, it doesn't move.
这条定律妙就妙在,如果只看定律的前半段,即,如果物体不受外力作用,将保持静止状态,你肯定会觉得,"这没什么,我能理解,因为你把一个物体放在那里,自己肯定不会动
应用推荐