Suddenly,without warning, a heavy mass of snow dropped down.

VOA: special.2010.05.01

You can't just start mass producing these drugs without paying a licensing fee."

你们不能就这样大规模生产,却不付任何专利费“

耶鲁公开课 - 公正课程节选

First one says, if you knew the force acting on any body, without going into what caused the force, then you may set that force equal the mass times acceleration of the body.

第一部分是,如果你知道作用在任一物体上的力,无论这个力的来源是什么,都可以令力等于质量乘以物体的加速度

耶鲁公开课 - 基础物理课程节选