The Historical Evolution of the Theory of Compass in China.
上海419论坛 指南针理论在中国历史上的.演变。
上海419论坛 The compass was invented in China two thousand years ago.
上海419论坛 中国在两千年前发明了指南针。
The electronic compass is widely used in the navigation equipments recently.
上海419论坛 近年来,电子指南针被广泛的运用于导航设备中。