甲烷和丙烷是烷烃。Methane and propane are alkanes.丙烷气钢瓶a propane gas cylinder亚胺基杂环丙烷季铵盐的阳离子,一定是按协同反应的方式开环的.The aziridinium ions must all be opened by a concerted process....
Three hundred thousand tons of cereals are needed to replenish stocks.需要30万吨谷类补充库存。They replenish the Xiakangjian flora and verify that this flora belongs to the Cathaysia - Gondwana mixed flora.等植物化石,进一步完善了夏康坚植物群的组合面貌,证...
...the transformation wrought by the technological innovations of the industrial age.由工业时代的新技术方法促成的变化Carpets, Rugs, Mats and Durries, General Collectables, Wrought Iron.采购产品地毯, 毯子, 垫和棉花地毯, 牛仔裤藏的物品, 铸铁.The rattan and wrou...