english: Now, just as every cell requires nutrients to fuel it, every cell also produces waste as a byproduct, and the clearance of that waste is the second basic problem that each organ has to solve.
non_english: Kao što svakoj ćeliji trebaju hranljive materije, tako i svaka proizvodi otpadne materije, a čišćenje tog otpada je drugi problem koji svaki organ mora da reši.