Conservationists occasionally light forests on fire to control wild fires. By occasionally burning material (like leaves, branches, etc), those materials cannot build up and cause large and uncontrollable fires later.
Answer: D
They often occur spontaneously, because when energy is released during a chemical reaction it does not usually happen slowly.
Option B. A man pushes a couch across the room is the answer.
I would think its B but im not positive
