What is more, the primary geomagnetic field has lessened by nearly 10 percent since it was first measured in the 1830s.是什么意思_What is more, the primary geomagnetic field has lessened by nearly 10 percent since it was first measured in the 1830s.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句