下列各组中的含氧酸与其对应的酸酐,错误的是 A.CH3COOH的酸酐是(CH3C 发布时间:2017-05-14 20:54 │ 来源:www.tikuol.com 题型:选择题 问题: 下列各组中的含氧酸与其对应的酸酐,错误的是 A.CH3COOH的酸酐是(CH3CO)2OB.HPO3的酸酐是P2O5C.HNO2的酸酐是NO2D.HClO4的酸酐是Cl2O5
题型:选择题 He ________ have completed his work; otherwise, he wouldn't be enjoying himself by the seaside.[ ]A.should B. must C. wouldn't D.can't 查看答案
题型:选择题 气相色谱分析,内标法定量中,选择的内标物时要求()。A.内标物是易挥发的B.内标物在样品中是不存在的C.内标物在检测器中灵敏度高D.内标物的峰与被定量的峰相近E.内标物在溶剂中,溶解度大 查看答案