单选题
Even in times of prosperity, you cannot {{U}}waste money{{/U}} like this! It doesn't grow on trees.
A. let the money down the river B. let the money down the valley
D. let the money down the road D. let the money down the drain
【正确答案】
D
【答案解析】let one's money down the drain是个习惯用语，有“打水漂”之意，等于waste money。