passive gravitational mass

例句：

1. 1.The planet's gravity attracts the moon, causing it to orbit around it.
   行星的引力吸引月球，使其围绕行星旋转。
2. 2.The gravitational force between two objects is what determines their distance from each other.
   两个物体之间的引力决定了它们之间的距离。
3. 3.The gravitational pull of the Earth causes the Moon to orbit around us.
   地球的引力导致月亮绕着我们旋转。