poloidal magnetic field

例句：

1. 1. The polar bears are known for their ability to survivein the coldest of environments.
   北极熊因其在最寒冷环境中的生存能力而闻名。
2. 2.Antarctica is one of the world's last remaining ice sheets, coveringa vast expanse of land.
   南极洲是世界上最后一片未被破坏的冰原，覆盖着广阔的陆地。
3. 3. Polar bears are found only in theArctic and Antarctic regions.
   北极熊仅分布在北极和南极地区。