Magnetic compasses work as they do because the Earth itself is a magnet with a north-south field that causes freely moving magnets to align themselves with the field.是什么意思_Magnetic compasses work as they do because the Earth itself is a magnet with a north-south field that causes freely moving magnets to align themselves with the field.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句