The force of gravity makes things fall to earth.

地心引力使物体落向地面。

It is gravitation that causes the apple to fall.

地心吸引力使苹果下落。

The geotropism growth was a response of hypha to gravity and the geotropic sensitive was at the hyphal apex.

丛枝根真延伸生长部位尖端，其生长的向地性对地心引力的应，应的敏部位也在生长的尖端。

This dissertation presents the theory and method on the establishment of height datums.And some problems on the geocenter motion are also studied.

本文系统地研究了建立高的理论与方法、地心运动规律及其对高的影响等有关问题。

Height is a measurement at right angles to this surface, and though gravity pulls mainly toward the centre of the earth, the geocentre, there are local variations.

高一个垂直于这个表面的测度，而虽然重力总将物体向地心方向拉，但局部总会有一些变化。