时差N小时 枉费心机

If you want to fill a sink or bathtub with water, you need to do one thing first and that's stopper or plug up the drainpipe. Later, when you unplug the stopper, the used water will go rushing out down the drain¹. Hopefully, nothing valuable (such as a diamond ring) will be in that water, because after the water flows down the drain, it is gone forever. Anything that was mistakenly dropped into the water will therefore also disappear down the drain, and then it will be very difficult-probably impossible-to get it back.

如果你想把水槽或浴缸放满水，你需要做的第一件事这就是用塞子之类的东西堵住排水管。然后，当你拔掉塞子之后，用过的水就会漏进下水道里。我们都希望不要有什么贵重的东西（比如钻戒）掉在水里——因为水流进下水道之后，这些贵重东西永远也找不回来了。任何掉在水里的东西将最终落入下水道里——这将非常困难——恐怕不可能——把它找回来了。

From the sad reality of losing a cherished² object down a sink or bathtub drain comes this idiom, meaning to do or attempt to do something that ultimately³ will be lost forever. It can also mean to put great effort into a wasted activity.

通过这个直观的解释，我们理解了这个成语。它的意思是“做或试图做一些最终将永远失去的事情”。同时，它还含有“将巨大的努力浪费在无用的事情上”的意思。

1 drain   

n.排水沟，阴沟；消耗，负担；v.排去，放干

参考例句：

• Drain off the rest of the wine from this barrel.把桶里剩余的酒排出去。
• First,you have to drain the container of all the old oil.首先，你得从油箱中把所有的陈油都抽去。

2 cherished   

v.珍爱( cherish的过去式和过去分词 )；怀有；爱护；抚育

参考例句：

• Children need to be cherished. 儿童需要无微不至的爱护。
• She cherished a deep resentment under the rose towards her employer. 她暗中对她的雇主怀恨在心。 来自《简明英汉词典》

3 ultimately   

adv.最后地，最终地，首要地，基本地

参考例句：

• It was a demeaning and ultimately frustrating experience.那是一次有失颜面并且令人沮丧至极的经历。
• Vitamin C deficiency can ultimately lead to scurvy.缺乏维生素C最终能道致坏血病。