Why is the river rich?

Why is the river rich? why is the Yellow River yellow? why the river is so rich The river is two metres long 是否等于The river is two metres in length?Why? 英语脑筋急转弯：why is the river so rich? ? why is a river rich? Why was the river rich? 谜语:why is a river so rich? Why is a river very rich? Why the river is very rich?这是IQ题哦 小心! The Changjiang River is a f_______ river this river is the longestthis is the longset river区别 The Amazon River is the l____ river in the world The Yangtze River is the longest river in China 翻译 The Yellow River is the second（ ）river in China. Which is longer?The Yangtze River or The Yellow River? The longest river in China is the Changjiang River. The river in China is the Changjiang River