【单选题】You work for an national car rental agency and want to determine what characteristics are shared among your most loyal customers. To do this, you will want to use data mining software that is capable ...
【简答题】某化合物的分子式为C 7 H 7 O 2 N(A),无碱性,还原后得C 7 H 9 N(B)具有碱性。B在低温及强酸存在下,和亚硝酸作用生成C 7 H 7 N 2 Cl(C)。将此化合物C的水溶液加热时,放出N 2 ,并生成对甲基苯酚。在碱性溶液中,化合物C与苯酚作用生成具有颜色的化合物C 13 H 12 ON 2 ,请写出A、B、C、D的构造式和各步的反应式。