the beams with the same section of same materials in fig.(a) and fig.(b), and (b) is laminated beam, with no friction between layers. considering strength condition of the normal stress, the maximum load of beam (a) is( )times of that of beam(b)
单位成本随市场占有率的提高而下降时,市场占有率与收益率成正比。()
下列物质酸性最强的是
在一个完全竞争的市场上,劳动力需求的最优决策是劳动和资本的边际产品之比等于它们各自价格的反比。()
the maximum shear stress in the rod in tension and compression is 40mpa, then the maximum normal stress in the rod is equal to .
结构游戏也称建构游戏,开始于幼儿的
the capacity of a member to maintain its original equilibrium state under external load is the .
when subjected to a pair of forces of equal magnitude, opposite direction, and the line of action coincident with the axis of the member, the deformation of the member is .