Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to learn about the subject of thermodynamics as applied to chemical reactions [title] Define the term " thermodynamics ". [step] Thermodynamics is a science which is built upon experimental facts that cannot be proven. But no one has so far succeeded to refute these principles.

Ending1: It is important to define the term " thermodynamics " if you are trying to identify the actual material of certain thermodynamics. [substeps] The term " thermodynamics " is used to spell out thermodynamics. Ending2: There are two experimental facts upon which thermodynamics is built. These are: the law of conservation of energy upon which the first law of thermodynamics is built. Ending3: The concept of thermodynamics is static, and not very original. We are all on the same track here. Ending4: Understanding the term " thermodynamics " can help you construct an interesting cover or background to your entire lecture on thermodynamics. [title] Write a detailed introduction to thermodynamics.

Answer format: ending1/ending2/ending3/ending4