56.tA cylindrical container with a radius of 2R and a height of 2R contains liquid with a density of ρ,
filling 17/18 of its volume. When a plastic ball of radius R is placed m 1he liquid, the liquid perfectly fills tiie container witiiout any liquid spilled out. What is the density of the plastic ball in terms of ρ?
(A)ρ/4t
(B)ρ/3t
(C)ρ/2t
(D)3ρ/4t
(E)2ρ/3
答案：B
統計：A:0,B:1,C:0,D:0,E:0
難度：計算中