You're a team player; nothing great has ever been accomplished with just one person. Anyone who says otherwise is probably a not very nice person, and not someone who you feel the need to be associated with. You make friends for life, and you take those relationships very seriously. Like, blood oath seriously.
There is nothing that has been invented that we cannot live without. Because, for something to be invented we've had to not have had it before. People sure would piss and moan though if the car was taken away....to answer your question.
Water is absolutely essential to the human bodys survival. A person can live for about a month without food, but only about a week without water. Water helps to maintain healthy body weight by increasing metabolism and regulating appetite. Water leads to increased energy levels.