2.upheaval n.大变动(radical change)
3.upholstered a．装软垫的( to be furnished with or as if with upholstery)
4.upstate a．在州北部的(be in the northern sections of a state)
例：upstate New York纽约州北部地区
5.upstream ad.向上游 a．位于上游的(in the direction opposite to the flow of a stream)
例：The distribution of water allocations for irrigation is to prevent farms upstream from using water needed by farms downstream.
6.upsurge n．?#26412;?#19978;升(a rapid rise)
例：What accounts for this upsurge in unionization among clerical workers?
7.urbanization n．都市化(the quality or state of being urbanized or the process of becoming urbanized)
例：The populations of these cantons shared similar views because urbanization furthered the diffusion of ideas among them.
8.urbanize v.使…都市化（to cause to take on urban characteristics）
例:The influx of new businesses urbanized the small town．
9.urchin n.海胆(any of numerous echinoderms that are usually enclosed in thin brittle globular tests covered with movable s pines)
例：sea urchin 海胆