题目

下列烃完全燃烧生成CO2和H2O的物质的量之比为1：1的是 A．烷烃         B．（单）烯烃          C．（单）炔烃         D．苯的同系物 答案：B I now, we have raised 50.000 pounds for the poor children, ______ is quite unexpected.A．thatB．which C．whoD．it