英语 state the law of conservation of energy

请这样用英语回答：The law of conservation of energy is that a principle stating that the total energy of an isolated system remains constant regardless of changes within the system.For example, .....

请陈述“能量守恒”定律，并且解释其实际应用上的反应

陈述一下能源保护法并且解释它应用后的反应

陈述节能的有关法律,并解释其应用和反响