题目

衡量一国是否完成工业化，国际通常有三个指标，不属于的是（    ） A．农业产值占国民生总值的比重降到15%以下 B．农业就业人数占就业人数的比重降到20%以下 C．工业产值占国民生产总值比重超过60% D．城镇人口占总人口的比重超过60% 答案：C —Why does the lake smell terrible? —Because large quantities of water ______ .　 A. have polluted　 B. is being polluted　 C. has been polluted　 D. have been polluted