1·To query by distance, you must use a projected coordinate system.
要按照距离进行查询，必须使用投影坐标系。
2·If any of these assumptions are not valid for your database, you have to make adjustments that vary from trivial (for column names) to somewhat involved (in the case of a projected coordinate system).
如果这些假设对于您的数据库不成立，那么必须做某些调整，这些调整可能很简单(比如对于列名)，也可能比较复杂(比如对于投影坐标系)。
3·If it is the region of integration then it will go into the bounds of the integral and maybe in the choice of the coordinate system that you use for integrating.
如果给出了积分区域，你就要找出积分边界，也许通过选择适当的坐标系来做。
4·The coordinate system, for 2-d graphics, is shown in Figure 2.
2 - D图形的坐标系如图2所示。
5·Remember that I placed the cube's center at the coordinate system's origin; therefore, the cube's edges will be two units long.
由于我将立方体的中心点放在坐标系原点位置处，因此立方体的各边长应为 2 个单位。