w88中文专业四级阅读理解模拟题81(含答案)

migration is usually defined as "permanent or semipermanent change o f residence".

"this broad definition, of course, would include a move across the street or a cross a city. our concern is with movement between nations, not with internal mi gration within nations, although such movements often exceed international movem ents in volume. today, the motives of people who move short distances are very s imilar to those of international migrants".

students of human migration speak of "push" and "pull" factors, which influe nce an individual's decision to move from one place to another. push factors are associated with the place of origin. a push factor can be as simple and mild a matter as difficulty in finding a suitable job, or as traumatic as war, or sever e famine. obviously, refugees who leave their homes with guns pointed at their heads are motivated almost entirely by push factors (although pull factors do in fluence their choice of destination).

pull factors are those associated with the place of destination. most of thes e are economic, such as better job opportunities or the availability of good lan d to farm. the latter was an important factor in attracting settlers to the unit ed states during the 19th century. in general, pull factors add up to an apparen tly better chance for a good life and material well?being than is offered by th e place of origin. when there is a choice between several attractive potential d estinations, the deciding factor might be a non?economic consideration such as the presence of relatives, friends, or at least fellow countrymen already establ ished in the new place who are willing to help the newcomers settle in. consider ations of this sort lead to the development of migration flow.