题目

阅读理解Withoil prices rising sharply this year, it seems remarkable to argue that watermight one day be more expensive than oil. Jean-Louis Chaussade, the chiefexecutive of the French utility company Suez, argues that water scarcity(不足）is now one of the most pressing challenges facing many industries.He told the Financial Times last year that he foresaw one day water would bemore precious than oil.Itisn't only a growing world population that places demands on water - industriessuch as energy and agriculture are also consuming more and more. The 2030 WaterResources Group, believes th如果我国发射的某人造地球通讯卫星离地面的高度是36000km，那么某电视台播出的节目信号到达卫星后，再从卫星返回到地面上的“锅盖”接收天线处，一共需要多长的时间？