Questions 17～20 are based on the following passage about the meaning of a satisfactory standard of living. You now have 20 seconds to read the questions 17～20. Why are we far from satisfied with our basic needs

A．Because we should save extra money for future expenditure.
B．Because we have other wants in addition to our basic needs.
C．Because we all enjoy reading books.
D．Because man is never satisfied even if he has everything he wants.