A.SELECTTOP2*FROM商品WHERE部门号=“40”GROUPBY单价;
B.SELECTTOP2*FROM商品WHERE部门号=“40”GROUPBY单价DESC;
C.SELECTTOP2*FROM商品WHERE部门号=“40”ORDERBY单价;
D.SELECTTOP2*FROM商品WHERE部门号=“40”ORDERBY单价DESC;