why is a river rich到底是什么啊!

why is a river rich? 谜语:why is a river so rich? Why is a river very rich? Why is the river rich? 一到英语智力题Why is a river rich?Because it has two ______. 翻译以下到中文 Why is a river rich? Because it has two banks why is a river so rich?iq题 (脑筋急转弯)Why is a river rich?用汉语回答. why is a river rich到底是什么啊! why the river is so rich Why is a river very rich?為什么河這么富有?英语 加 汉语 的 回答. 英语脑筋急转弯：why is the river so rich? ? English RiddleWhy is a river very rich? Why was the river rich? 英语谜语:Why is a river rich?什么东东啊.乱起把早,哪位厉害点帮一西啊 What is more useful after it is broken?Why is a river rich?Which table has no legs?请尽可能用英语回答啊, why do we say that a river is very rich?what will she do if a man-eating tiger is running after her Why the river is very rich?这是IQ题哦 小心!