题干
—Della likes dancing, but doesn't like swimming.
—____________.
A：So does Mary
B：Neither does Mary
C：So it is With Mary
D：Nor does Mary
答案(点此获取答案解析）
C
—Della likes dancing, but doesn't like swimming.
—____________.
A：So does Mary
B：Neither does Mary
C：So it is With Mary
D：Nor does Mary
在（0，+∞）上都是减函数，则y=ax2+bx在（0，+∞）