magnetic prime vertical

例句：

1. 1.The magnetic field lines are perpendicular to the Earth's surface.
   磁场线与地球表面垂直。
2. 2. The magnetic poles are located at the geographic north and south poles.
   磁极位于地理北极和南极。
3. 3. The magnetic field is responsible for the movement of charged particles in space.
   磁场负责空间中带电粒子的运动。