A: certain nutrient might has two or three nutritional functions that is: it can be used as the source of carbon,::::nitrogen or energy,: while some: only have one function Monofunctional nutrient)--ray irradiation energy (单功能营养物 energy source Bifunctional nutrient)= deoxidized(还原态的) inorganic NH (双功能营养物 energy source and nitrogen source) Trifunctional nutrient)--amino acids ∈三功能营养物 source of carbon, nitrogen and energy)Monofunctional nutrient)——ray irradiation energy （ 单功能营养物 energy source） Bifunctional nutrient)——deoxidized（还原态 的）inorganic NH4 (双功能营养物（energy source and nitrogen source） Trifunctional nutrient)——amino acids (三功能营养物 source of carbon， nitrogen and energy） A certain nutrient might has two or three nutritional functions，that is ,it can be used as the source of carbon， nitrogen or energy，while some only have one function