填空题

It is evident that high degrees of mobility can have strongly negative effects on society as a whole. Social scientists emphasize that, in our 【B1】 mobile society, there is also an 【B2】 neglect of the maintenance of 【B3】 quality — a disregard that seems to 【B4】 from a lack of performance and a attachment to place. The 【B5】 home has become, for millions of Americans, a 【B6】 place, no longer the base of successive 【B7】 . The tightly knit fabric of neighborhoods has become 【B8】 . it is not usual for people to be 【B9】 to those living on the same block or even 【B10】 door. Impermanence, transience, and uncertainty 【B11】 the length of stay in any particular place) have 【B12】 people’’s responsibility for the 【B13】 of their homes and neighborhoods, investment values, however. Even more serious is the impact of out-migration 【B14】 neighborhoods and whole urban areas 【B15】 by substantial numbers of their inhabitants. The 1980 U.S Census 【B16】 large population declines for the country’’s northern central cities, 【B17】 population outflow that result in 【B18】 housing and boarded-up business — and, 【B19】 . in reduced federal support for 【B20】 urban areas already in financial difficulty.