The typical pre-industrial family not only had a good many children, but numerous other dependents as well — grandparents, uncles, aunts and cousins. Such "extended" families were suited for survival in slow paced (47) societies. But such families are hard to (48) . They are immobile. Industrialism demanded masses of workers ready and able to move off the land in pursuit of jobs, and to move again whenever necessary. Thus the extended family (49) shed its excess weight and the so- called "nuclear" family emerged — a stripped-down, portable family unit (50) only of parents and a small set of children. This new style of family, far more (51) than the traditional extended family, became the standard model in all the industrial countries. Super-industrialism, however, the next stage of eco-technological development, (52) even higher mobility. Thus we may expect many among the people of the future to carry the streamlining process, a step further by remaining children, cutting the family down to its more (53) components, a man and a woman. Two people, perhaps with matched careers, will prove more efficient at navigating through education and social status, through job changes and geographic relocations, than the ordinarily child-cluttered family. A (54) maybe the postponement of children, rather than childlessness. Men and women today are often torn in (55) between a commitment to career and a commitment to children. In the future, many (56) will side aside this problem by deferring the entire task of raising children until after retirement. A. transplant B. solution C. gradually D. transport E. elemental F. conflict G. continually H) mobile I) couples J) agricultural K) including L) compromise M) requires N) primary O) consisting