Obviously we don't expect you to know exactly what the distances are, but you should be able to compare them relatively.

当然我们不要求你么,要能知道具体这些位置是多少，但你们要能够相对比较它们。

麻省理工公开课 - 化学原理课程节选

I think it's clear, the position of the object with respect to the ground, this vector is the same as the position of the object with respect to the plane, plus the position of the plane with respect to the ground.

我觉得很明显,物体相对于地面的位置,这个矢量等于,物体相对于平面的位置矢量,加上物体相对于地面的位置矢量

耶鲁公开课 - 基础物理课程节选