4. (1)Andy and Sharon live in a small house with their two children in rural farm country. (2)Andy farms and works part-time in the local grocery store, while Sharon works part-time as a cook in a diner. (3)Although they earn only about $20,000 a year, they're happy, have the things they want, and think of themselves as doing pretty well. (4)Leslie recently moved to the "big city" to attend a private college. (5)Although her parents pay all her expenses and give her $750 a month for "extras," Leslie constantly complains about how difficult it is to be poor, and many of her affluent friends feel the same way. (6)Keith, a struggling young actor, works part-time nights as a guard and supports himself on about $900 a month. (7)It's a difficult task, but Keith is happy with his life and considers himself economically comfortable. (8)By the government's economic measurement, all these people except Leslie would be considered poor. (9)Yet it is Leslie who feels poor. (10)To a great extent, whether or not people consider themselves poor depends upon their expectations and the economic conditions of those around them.The sentence that expresses the main idea is: