大家知道,在出现飞机和航空测量技术以前,绘制准确的地图是一件十分困难的事情。人们只能运用几何技术,通过许多测量基点,来确定各个城市之间的距离、地形的高低、边境线和海岸线的形状等等。往往为确定一个地区的经纬度而消耗一个人的毕生精力。所以,直到近代,才有比较准确的地图出现。如南北美洲的比 As you know, it is a very difficult task to map accurately before the advent of aircraft and aerial survey techniques. People can only use geometric techniques to determine the distance between cities, the level of the terrain, the shape of the borderline and the coastline, and so on through many measurement points. Often, a person’s lifelong energy is consumed in determining the latitude and longitude of a region. So, until modern times, there is more accurate map appears. Such as North and South America than