Newton's law of universal gravitation

例句：

1. 1. The law of gravity explains why objects fall towards the center of the Earth.
   万有引力定律解释了为什么物体会向地球的中心下落。
2. 2. This law is fundamental to understanding the structure of the universe.
   这一定律是理解宇宙结构的基础。
3. 3. Newton's law of universal gravitation has been proven by countless experiments.
   牛顿的万有引力定律已经被无数的实验证明。