1.Jobs and work do much than most of us realize to provide happiness and contentment
2.We are much less conscious of the extent to which work provides the more crucial psychogical well-being that can make the difference between a full and empty life.
3.Work is more than a necessity for most human beings;it is the focus of their lives，the source of their identity and creativity.
4.Rather than a punishment or a burden，work is the opportunity to realize one’s potential.
5.Many Americans choose to travel by car rather than by any other means of transportation
6.Generally speaking，young people are less conservative than old people
7.The more scientists find out，the more questions they are unable to answer.