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.
Un râu canalizează fluxul de apă, fulgerul din nori canalizează fluxul de electricitate, iar o frunză e concepută să canalizeze fluxul de nutrienţi către arbore, uneori trebuind să ocolească un obstacol, dar asigură acest flux.