她紧紧地抓着栏杆,小心翼翼地爬楼梯。She climbed the staircase cautiously, holding fast to the rail.他失去平衡,往后趔趄了一下,撞到栏杆摔倒了。He lost his balance, staggered back against the rail and toppled over.他把一根拐杖靠在栏杆上。He rested one of his crutches again...
In the presence of ethanonitrile and glycol, anisole reacts with ammonium ceric nitrate to form o - nitroanisole.在乙腈、聚乙二醇存在下, 用苯甲醚与硝酸铈铵反应合成了邻硝基苯甲醚.Calcium reacts with water.钙和水会发生化学反应。Once in water, it reacts to form car...