GEabbr.美国通用电气公司（=General Electric Coabbr.地面设备（=ground equipment）abbr.锗（=germanium）GECTA=generalized error-correcting tree automation 广义的误差校正树状自动机

1. 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.
   高程是一个垂直于这个表面的测度，而虽然重力总是将物体向地心方向拉，但局部总会有一些变化。