adj.无回报的，未果的，未获成功的

Despite his hard work, he felt unrewarded and unappreciated by his employer.
尽管他工作努力，但他觉得没有得到雇主的奖励和赏识。
She devoted years to the project, but unfortunately her efforts went unrewarded.
她为这个项目倾注了多年心血，但不幸的是，她的努力没有得到回报。
The detective spent months on the case, only to find it was an unrewarded pursuit.
侦探在这个案件上花费了几个月的时间，结果却发现这是一场没有成果的努力。
His dedication to the cause was remarkable, yet it seemed to go unrewarded in terms of recognition.
他对这项事业的奉献精神令人钦佩，但在获得认可方面似乎没有得到相应的回报。
The athlete trained tirelessly for the competition, but an injury left her efforts unrewarded.
这位运动员为了比赛不辞辛劳地训练，但伤病使她的努力未能得到回报。
Many artists struggle in obscurity, their talents going unrewarded until long after their death.
许多艺术家在默默无闻中奋斗，他们的才华直到去世后很久才得到认可。
Despite submitting numerous job applications, he found himself in a cycle of unrewarded job searching.
尽管提交了许多份工作申请，他发现自己陷入了一个没有成效的求职循环中。
The teacher's patience with difficult students often felt unrewarded, but she continued out of a sense of duty.
老师对难搞的学生所展现的耐心常常感觉没有得到回报，但她出于责任感还是坚持了下来。
The inventor poured his life savings into his invention, but market indifference left him feeling unrewarded.
发明家把毕生积蓄都投入到了发明中，但市场的冷漠让他感到自己的努力没有得到应有的回报。
Volunteering can sometimes feel like an unrewarded task, but the personal satisfaction it brings is invaluable.
志愿服务有时可能让人感觉像是没有回报的任务，但它带来的个人满足感是无价的。