have high population growth. Those people need to go somewhere else.

　　There are three main reasons why people move. The basic categories and percentages are as follows, according to the Current Population Surveys (CPS):

　　Family-related reasons account for 26.3%, including changes in marital（婚姻的） status, establishing a household and other family reasons; work-related reasons 16.2%, including job transfer, retirement, and other job-related reasons; housing-related reasons 51.6%, including new and better houses, better neighborhood, cheaper housing and other housing reasons; the remaining 5.9% of other reasons are attending college, the change of climate and health reasons.

　　Americans have been migrating south and west for decades in search of better job opportunities and warmer climates. They have also been moving to places a little far from cities, in search of bigger yards and houses, lower crime rates and better schools. In 1950, nearly a fifth of the population lived in the nation's 20 largest cities. In 2006, it was about one in ten. That's why many American people say, "Big Cities Shrink as People Move South, West."

　　Between March 2005 and March 2007, 73.4 million Americans moved. Fifty-six percent of these moves were within the same country. Twenty percent were between counties but in the same state. Nineteen percent were moves to a different state. Some families even went abroad.

　　Title: People on the 71

　　Lead-in 　　Throughout human 72 , people have migrated across continents. 　　 　　An 73 number of people from poor countries are moving to ______74 countries, especially neighboring ones. 　　75_ for people's migration 　　According to the CPS, the 76 of people move to other places for reasons 77 to housing. 　　 　　Americans have long been moving south and west, looking

　　 78 a better job chance, a warmer 79 and a bigger yard, etc.