(1)甲、乙两圆柱体对桌面的压力之比: F甲 F乙 = G甲 G乙 = m甲g m乙g = m甲 m乙 = 1 2 ,故B正确、A不正确;(2)圆柱体对水平桌面的压强为p= F S = G S = mg S = ρVg S = ρShg S =ρgh,则 p甲 p乙 = ρ甲gh甲 ρ乙gh乙 = ρ甲 ρ乙 × h甲 h乙 = 3 2 × 4 1 = 6 1 ,故C正确、D不正确.故选BC.