分别由甲、乙两种物质组成的不同物体，其质量与体积的关系如图所示．分析图象可知，两种物质的密度之比ρ_甲：ρ_乙为（　　）

    During holidays，Kitty usually goes to see the exhibits in many museums，such as the history museum，the art museum，the museum of science and technology and the museum of natural history．There are thousands of wonderful things in museum.There are paintings，sculptures(雕塑)，costumes(服饰)，swords(剑)，ancient animal bones and plants，stuffed animals(动物标本)and many others．It is always a good review of history to visit those museums．It is also a great way to learn more things by myself．

已知反比例函数$y=\frac{1-2m}{x}$的图象上两点A(x₁，y₁)，B(x₂，y₂)，当x₁＜0＜x₂时，有y₁＜y₂，则m的取值范围是 （   ）