In the lower Van Allen Belt, the proton intensity is about 20,000 particles with energy above 30 MeV per second per square centimeter.是什么意思_In the lower Van Allen Belt, the proton intensity is about 20,000 particles with energy above 30 MeV per second per square centimeter.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句