当数据主要按产品组排序时，为产品表选择合适的查询。ProductGroup应按升序显示，CurrentStock应按降序显示：( )
Select * from Products order by CurrentStock,ProductGroup
Select * from Products order by CurrentStock DESC,ProductGroup
Select * from Products order by ProductGroup,CurrentStock
Select * from Products order by ProductGroup,CurrentStock DESC
都不是
