将已定义的图块或图形文件插入到图形中,AutoCAD默认的快捷键是()。
A.Ctrl
B.In
C.P
D.I
参考答案:D
A.Because more and more people move into big new houses.
B.Because many old people sell their house after their children leave.
C.Because people want to sell the old house to get money and build their own house.
D.Because children often ask their parents to sell the old house.
如图所示,质量均为2.4千克的薄壁圆柱形容器A和B放在水平地面上,底面积分别为2×10-2米2和1×10-2米2。容器A中盛有0.1米高的水,容器B中盛有质量为1.6千克的酒精。(ρ酒精=0.8×103千克/米3)求:
①容器B中酒精的体积V酒精。
②容器B对水平地面的压强pB。
③现有质量相等的甲、乙两实心物块,若将甲浸没在水中、乙浸没在酒精中后,两液体均未溢出,且两液体各自对容器底部压强的变化量相等,求甲、乙的密度ρ甲、ρ乙之比。