【简答题】烧结普通砖的尺寸为240mm×115mm×53mm,已知其孔隙率为37%,干燥质量为2487g,浸水饱和后质量为2984g。试求该砖的体积密度、密度、吸水率。
【判断题】The forged parts are stronger than cast parts of same material.
【单选题】The forged parts are than cast parts of same material.
【判断题】The forged parts are not tougher than machined parts of same material.
【判断题】The surface finish of forged parts are better than casting.
【判断题】The dimensional control of forged parts are wore than casting.
【单选题】某只个股的β系数为- 0.8 ,则意味着 ( )