(1)写出图中字母所代表的水电站及所在的省级行政区名称: A_________、_________;B_________、_________;C_________、_________; D_________、_________;E_________、_________;F_________、_________; (2)许多大水电站都建在阶梯分界线上,你知道其中的原因吗? _______________________________________________________________________________________ |