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....
He started working for a gallery sweeping up and making the tea.他开始在画廊做扫地沏茶的工作。"Thanks friend," he said, while sweeping the money into his pocket.“谢了，朋友，”他说着就把钱划拉进了口袋。A forest fire is sweeping across portions of north Ma...
the obstruction of justice妨碍司法公正The conical configuration of the appendix makes obstruction of the lumen unlikely.阑尾呈圆锥形,不易造成腔内梗阻.Obstruction or occlusion of a blood vessel an embolus.血液流经心脏和血管的运动.Anti - drying, to wrink...