The crucial point about the syllabus is that it indicates what reading you need to have done for any given week.

教学大纲的关键点,是指出了什么样的读物,你需要在给出的时间内完成。

耶鲁公开课 - 死亡课程节选

The fact that you don't need a force for it to move forever at a given speed in a given direction, that's not obvious, because in daily life you don't see that.

对于物体不需要力的作用就能保持,确定的速度和方向持续运动这一事实,它并非显而易见,因为在日常生活中你看不到这种情况

耶鲁公开课 - 基础物理课程节选