底面半径 2 厘米,高 3 厘米的圆柱,它的表面积和体积各是多少?
= :24=5:8= :40= %
3÷ ==0.75=6: = %
3÷ ==0.6=6: = %.
3:5==9: == .
=0.375=12÷ = %=0.45= %= ÷ .