These products have names like Red Bull, Monster,Ripped Force, Speed Stack and 5-Hour Energy.

VOA: special.2009.07.22

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

At that speed, the pressure is three times the force of gravity.

VOA: special.2010.07.07

The Navajo Nation has its own elders, laws,tribal government, and police force that is vigilant at enforcing speed limits.

VOA: standard.2010.03.22