全球导航卫星系统(GNSS)空间段采用MEO轨道卫星，未来将仍然以MEO为主，可能有HEO轨道卫星加入运行。

The MEO satellites are used in the GNSS space segment and in future will still be the mainstay in this segment possibly with the addition of the HEO (High-altitude Earth Orbit) satellites.

youdao

如果您在开发阶段加入这种类型的约束，在运行的时候模式验证器就会拒绝无效数据。

If you add this type of constraint at development time, the schema validator will reject the invalid data at runtime.

youdao

在运行程序之前，需要加入一些代码来驱动它。

Before you can run the program, you need to add code to drive it.

youdao