So a river is designed to channel the flow of water, and the lightning bolt that comes out of a cloud channels the flow of electricity, and a leaf is designed to channel the flow of nutrients to the tree, sometimes even having to route around an obstacle, but to get that nutrition flowing.
就如河可以引导水流 闪电可以引导电流 树叶则可以引导 树木中营养的流向 即使有时候需要绕过一些障碍 仍然在引导营养物质不停地流动