按类别查询图书的平均价格,以下语句正确的是()。(选择一项) A: selectavg(price),typefrombookgroupbytype B: selectcount(price),typefrombookgroupbyprice C: selectavg(price),typefrombookgroupbyprice D: selectcount(price),typefrombookgroupbytype
按类别查询图书的平均价格,以下语句正确的是()。(选择一项) A: selectavg(price),typefrombookgroupbytype B: selectcount(price),typefrombookgroupbyprice C: selectavg(price),typefrombookgroupbyprice D: selectcount(price),typefrombookgroupbytype
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