Studies by Park, Burgess, and other Chicago－school sociologists showed how new groups of i

Studies by Park, Burgess, and other Chicago-school sociologists showed how new groups of immigrants tended to be concentrated in separate areas within inner-city zones, where they sometimes experienced tension with other ethnic groups that had arrived earlier. Over time, however, each group was able to adjust to life in the city and to find a place for itself in the urban economy. Eventually many of the immigrants moved to unsegregated areas in outer zones; the areas they left behind were promptly occupied by new waves of immigrants.

Paragraph 6 indicates which of the following about the application of the Park and Burgess model to modern North American cities？

A．It is especially useful for those cities that have been used as models for international development.

B．It remains useful in explaining the development of some urban areas but not all cities.

C．It can be applied equally well to cities with commercial centers and those with palaces and cathedrals at their center.

D．It is less applicable to modern cities because of changes in patterns of immigration.

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