听力原文:M: Hello, I wonder if we could change the time for volleyball to Sunday. W: Is that the only time you can make it? Q: What call be inferred about the woman? (19)
【单选题】陈述A:SubQuery1 UNION SubQuery2语句,要求在执行该运算时参与运算的查询结果的列数一样,其对应列的数据类型必须一致。陈述B:GROUP BY和HAVING子句不能在子查询中使用,这些子句只能用在最后一个查询结束时来总结和排序最后结果集。关于陈述A和B,下列说法正确的是_________。