【简答题】(10分) 1 mol仅含C、H、O三种元素的有机物A在稀硫酸中水解生成1 molB和1 molC。B分子中 N (C)∶ N (H)=4∶5,135< M r(B)<140;C与B分子中C原子数相同,且 M r(B)= M r(C)+2。(1)C的分子式为 ,A的摩尔质量为 ; (2)B的分子具有高度对称性,苯环上的一氯取代物只有一种。B能与金属Na反应但不能与NaOH反应。写出B的结构简式 ;...
【简答题】Dear Aunty, After years of her crying, I finally gave in and allowed my daughter to have a cat. I now regret my decision. As someone needs to have a clean, tidy house, I no longer feel relaxed in my o...
【单选题】听力原文: One day my friend Jack and I were playing in the garden when I saw a cat in our big tree. It looked frightened and we thought it couldn't get down, so we climbed up to help it. We didn't have a ...