如果你现在离开学校，你所有的辛勤努力都将付诸东流。

If you leave the school now, all your hard work will go ___down ___the ___drain.

我以为所有那些晚间谈话和10万日元的投资都打了水漂。

All those evening conversations and the investment of 100,000 yen went ___down ___the ___drain, I thought.

当实验失败时，多年的研究都白费了。

The years of research went ___down ___the ___drain when the experiment failed.