A system of 4 communicating vessels with equal-diameter vertical tubes is filled with oil (oil-like (medium viscosity)), which appears yellow in color. As shown in the initial frame, the liquid levels in the tubes are [59, 33, 19, 15] cm respectively. Due to pressure differences between the tubes, the liquid begins to flow through the connecting channels at the bottom. The flow is governed by hydrostatic pressure equalization and damped by viscous resistance with coefficient k=2.29. As the liquid redistributes, the height differences gradually decrease, and the system evolves toward equilibrium. Eventually, through conservation of volume, all tubes reach the same final liquid level, which equals the average of the initial heights. Only modify what the task requires; keep the background and any other element unchanged. Output 4 images showing the liquid levels at uniform time progress during equalization.