题目解析:
用两个人名来定位,定位到:Presociological thinkers like Frederick Law Olmsted, the founder of the movement to build parks and recreation areas in cities, and Jacob Riis, an advocate of slum reform, urged the nation's leaders to invest in improving the urban environment, building parks and beaches, and making better housing available to all. 由此可以看出,Olmsted 和 Riis 都希望 improving the urban environment(改进城市环境),也就是想要 improve the conditions of life(改善城市生活条件)。所以选择 C。A 选项的 empirical research 是其他 sociologists 做的,不是他们两个的共同点;B 选项无提及,D 选项的 reduce the rapid growth 无提及。