Often, it is something global like WGS-84 (World Geodetic System 1984, used by all GPS devices), or a regional datum like NAD-83 (North American Datum 1983).

它常常是全球大地基准点（比如 WGS-84，即 World Geodetic System 1984，由所有 GPS 设备使用），或地区性大地基准点（比如 NAD-83，即 North American Datum 1983）。

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Her world revolved around the stable datum of her Polish-Catholic culture.

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