Eng: An object...

物體在受到外力作用之前保持零加速度

An object has zero acceleration until acted on by an external force (Law of Inertia)

物體在受到外部力作用之前具有零加速

An object has zero acceleration until acted on by an external force (Law of Inertia)

物體在未受外力作用時保持恆定速度

An object maintains a constant velocity when no external forces act upon it (Newton's first law of motion)