We only observe the small portion of the magnetic field that extends to the surface and beyond, where its basic structure is a dipole that is, a simple north south field like that of a simple bar magnet.是什么意思_We only observe the small portion of the magnetic field that extends to the surface and beyond, where its basic structure is a dipole that is, a simple north south field like that of a simple bar magnet.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句