(脑筋急转弯)Why is a river rich?

(脑筋急转弯)Why is a river rich? why is a river rich? Why is a river very rich? Why is a river rich?Because___________ why is a river so rich? 谜语:why is a river so rich? 英语谜语:Why is a river rich? Why is the river rich? 英语趣味回答：why is river rich? Why the river is very rich? why the river is so rich What is more useful after it is broken?Why is a river rich?W