某油库装煤油的油罐中盛有4m深的煤油,在距底部0.5m处发现有一面积为10cm2的圆形漏油孔.(ρ油=0.8 g/cm3)求:
—Mum, I am hungry.
—Here is a for you. Why not help yourself to it?
关于我国基本国情的叙述,正确的是( )