The definition of the coastal line (datums of island, uncoverd neaf and lighthouse) is more clarified on the basis of scientific location.

在科学选址的基础上，对海岸线（岛屿基准面，明礁和灯塔）的定义更加明确。

When a dimension's origin is in doubt use the datums specified.

当不能确定尺寸原点时，使用规定的基准。

It offers detailed datums for understanding and using magnesium.

为进一步认识镁，更好地利用镁提供了较为详细的资料。

Numbers of datums can once be handled in PC-1500 by this method.

这种方法可从PC-1500上一次处理大批数据。

The datums tasted by using these three methods can all be used as the bases for the treatment.

三种方法测出的数据，都可作为处理的依据。