在水平桌面上有一个盛有水的容器,木块用细线系住没入水中(水未溢出),如图甲所示.将细线剪断,木块最终漂浮在水面上,且五分之二的体积露出水面,如图乙所示.
下列说法正确的是( )
A:甲、乙两图中,木块受到水的浮力之比是5:2
B:甲、乙两图中,水对容器底部的压强之比是1:1
C:甲图中细线对木块的拉力与木块受到的浮力之比是 2:5
D:甲、乙两图中,容器对水平桌面的压强之比是5:3
若y=x-1+1-x﹣2,则﹣xy的值为( )
- Our head teacher is responsible for his work. He spends most of his time with us.
- ________ He always communicates with our parents in his free time.
进人初中 ,老师、父母对我们的要求高了,期望高了,这是因为( )