down 失意，低谷，挫败

　　Life is full of ups and downs.

　　人生充满着起起伏伏。

　　He went through a lot of ups and downs.

　　他经历了很多起起伏伏。

　　you look so down today, are you ok?

　　你今天看起来情绪很低落啊，你还好吗？

　　疯狂练习吧！