题目

下列物质属于酸性氧化物的是                              (   )A．Fe2O3         B．SO2            C． Al2O3        D．CO  答案：B解析:略  If not ________, you can return everything on the spot and no further duties when you purchase goods at www．amazon．cn． [　　] A． to satisfy B． being satisfied C． satisfied D． satisfying