There was a time __________ the people in my village lived a peaceful life, enjoying the beauty of nature.

A．which

B．when

C．that

D．where

节水型社会建设“十一五”规划指出，属于约束性指标的是( )。

A．农田灌溉水有效利用系数

B．城市供水管网漏损率

C．单位GDP用水量

D．单位工业增加值用水量