Gasoline igniting doesnt change physically, wood rotting is just it getting old i guess, i would say d because its from water to vapenation. im really bad in school so im not sure but i decided to answer
Enzymes lower the activation energy of a chemical reaction.
Answer:
When calcium concentration increases during depolarization, it shifts the conformation of troponin and tropomyosin, and actin is able to associate with myosin. As calcium is taken up again by the sarcoplasmic reticulum the muscle cell relaxes.