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.
All people need food to live. Sometimes a person cannot eat any or enough food because of an illness. Others may have a decreased appetite, difficulties in swallowing, or some type of surgery that interferes with eating. When this occurs, and one is unable to eat, nutrition must be supplied in a different way.