Define what negligence is, and what four elements does the plaintiff, who fell over a slippery banana peel, have to prove against the Defendant Grocery Store to succeed in a claim of negligence against that Defendant? Does it matter if the banana peel has only been on the floor for five minutes as opposed to four hours, and why? What are the defenses of assumption of the risk, comparative negligence, and contributory negligence, and give an example of each?