More than 20 types of metallic elements were discovered in XC gas field, Sichuan Basin, when it was studied by neutron activation analysis (NAA).是什么意思_More than 20 types of metallic elements were discovered in XC gas field, Sichuan Basin, when it was studied by neutron activation analysis (NAA).在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句