In a broad sense，migration is usually defined as "permanent or semi-permanent change of residence"．Although movements within nations （internal migration） often exceed movements between nations （international migration） in volume，the motives of people who move short distances are very similar to those of international migrants．
Students of human migration speak of "push" and "pull" factors，which influence 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 severe famine．Obviously，refugees who leave their homes with guns pointed at their heads are motivated almost entirely by ush factors．
Associated with the place of destination，pull factors are mostly economic，such as better job opportunities or the availability of good land to farm．In general，pull factors add up to an apparently better chance for a good life and material well-being than is offered by the place of origin．When there is a choice between several attractive potential destinations，the deciding factor might be a non-economic consideration such as the presence of relatives，friends，or at least fellow countrymen already established in the new place who are willing to help the newcomers settle in．Considerations of this sort lead to the development of migration flow．
Besides push and pull factors，there are what the sociologists call "intervening obstacles"．Even if push and/or pull factors are very strong they still may be outweighed by intervening obstacles，such as the distance of the move，the trouble and cost of moving，the difficulty of entering the new country，and the problems likely to be encountered on arrival．
The decision to move is also influenced by "personal factors" of the potential migrant．The same push-pull factors and obstacles operate differently on different people，sometimes because they are at different stages of their lives，or just because of their varying abilities and personalities．The prospect of packing up everything and moving to a new and perhaps very strange environment may appear interesting and challenging to an unmarried young man and terribly difficult to a slightly older man with a wife and small kids．Similarly，the need to learn a new language and customs may excite one person and frighten another．
Regardless of why people move，migration of large numbers of people causes conflict．The newest arrivals are usually given the lowest-paid jobs and are resented by native people who may have to compete with them for those jobs．It has usually taken several decades for each group to be accepted into the mainstream of society in the host country．

Migration
Passage outline	Supporting details
Broad （71） definition definition of migration	Migration is permanent or semi-permanent change of residence． 72） More More people move within nations than between nations，yet their motives are alike．
Factors in migration	Push factors	（73） Unable Unable to find a suitable job or suffering from war or natural disaster，people are likely to leave their homeland．
	Pull factors	74） Motivated/Influenced Motivated/Influenced by pull factors，people are desperate for more chances to live a better life in the place of destination． Earlier settlers tend to offer help to new migrans，greatly （75） promoting promoting migration flow．
	Intervening obstacles	（76） Strong Strong as push and pull factors might be，intervening obstacles seems more difficult for some to （77） overcome overcome ．
	Personal factors	International migration may be interesting to those unmarried but not to those with a family；the same （78） thought/ prospect thought/ prospect of picking up a foreign language may make one excited but another frightened．
Impacts of migration	As a result of large numbers of the newest arrivals，conflicts between them and the natives will （79） arise/occur/appear arise/occur/appear ．It usually takes long for the new comers to （80） fit fit in with the mainstream of the host country．