题目

有机物A可由葡萄糖发酵得到，也可从酸牛奶中提取。纯净的A为无色黏稠液体，易溶于水。为研究A的组成与结构，进行了如下实验：实验步骤解释或实验结论(1)称取A 9.0 g，升温使其汽化，测其密度是相同条件下H2的45倍。试通过计算填空：(1)A的相对分子质量为：________      。(2)将此9.0 g A在足量纯O2中充分燃烧，并使其产物依次缓缓通过浓硫酸、碱石灰，发现两者分别增重5.4 g和13.2 g。(2)A的分子式为：________            。(3)另取A 9.0 g，跟足量的_________ snacks and drinks,but they also brought cars for entertainment when they had a picnic in the forest.? A.Not only they brought　　　　　　 B.Not only did they bring? C.Not only brought they　　　　　　 D.Not only they did bring?