gravity可数吗
例句
Nothing is pulling on you, only gravity.
没有任何东西在拉你，只有重力。
With no gravity, its just as easy to pedal.
在没有重力的情况下，踩起踏板来很容易。
The stone rolled down the mountain by gravity.
这块石头由于重力作用而滚下山。
Gravity had always been, but Newton \"discovered\" it.
引力一直都是存在的，但是是牛顿“发现”了它。
Otherwise gravity will pull you back down to the Earth.
否则，地心引力会把你拉回地球。
It is to get the rocket going fast enough to escape Earth\'s gravity.
是为了让火箭的速度足够快，足以逃离地球的引力。