以下是测定菜油密度的实验步骤:(1)用天平测出空矿泉水瓶的质量m;(2)在矿泉水瓶中装满水,用天平测出总质量m
1;(3)在矿泉水瓶中装满菜油,用天平测出总质量m
2;(4)将菜油全部倒入量筒中,用量筒测出矿泉水瓶里所盛菜油的体积V
1;(5)将菜油倒入量筒中,测出剩余菜油和瓶的总质量m
3;(6)读出量筒中所盛菜油的体积V
2;(7)计算菜籽油的密度。有三个实验小组分别选用其中部分实验步骤测量出菜油的密度,并写出表达式:(ρ
水已知)①ρ=
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmfrac%3E%3Cmrow%3E%3Cmsub%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmsub%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmsub%3E%3Cmi%3EV%3C%2Fmi%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmsub%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
②ρ=
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmfrac%3E%3Cmrow%3E%3Cmsub%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmsub%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmsub%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmsub%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmsub%3E%3Cmi%3EV%3C%2Fmi%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmsub%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
③ρ=
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmfrac%3E%3Cmrow%3E%3Cmsub%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmsub%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmsub%3E%3Cmtext%3Em%3C%2Fmtext%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmsub%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
,你认为较合理且误差较小的表达式是( )