题目

It's time to be water efficient!    As populations increase acrossAustralia and the rest of the world, demand for water will also increase. If we don’t reduce each individual’s demand for water (both directly and through embodied water) the water situation will become dire.     It is obvious that we cannot increase demands for water much more without detrimental(有害的) effects to the environment, society and the economy.     It’s all too easy to blame someone else for the water situation –“if 70% of water is used for agriculture then that’s what we should target” 地球自转的周期 [     ]A、约24小时 B、12小时 C、一年 D、一个月