{"lablename3":"六年级数学","title":"在一块铜和锡的合金中,铜和锡的重量比是5∶3。已知合金的重量是400千克...[六年级][数学]","mkid":"","lablename2":"六年级","pagetype":3,"infoid":"2481924","infotype":0,"lablename1":"小学"}