宇宙中的每一个物体都将另一物体拽向自身。这叫引力。但那个拉力(引力)的强度取决于两个因素。首先,它取决于一个天体所含物质的多少。一个天体(物体)所含的物质多,它的引力就大。一个天体所含的物质很少,它的引力也很小。比如,地球比月球物质多,所以地球的拉力或引力就比 Every object in the universe twists another object toward itself. This is called gravity. But the strength of that pull (gravity) depends on two factors. First, it depends on how much material an celestial body contains. An celestial body (object) contains many substances, and its gravity is great. A celestial body contains very little material, and its gravity is also very small. For example, Earth has more material than the Moon, so the Earth’s pull or gravity is better than