complainer

基本解释

If you are a complainer, or focus on problems, change your focus now.
如果你是一个爱抱怨的人，或者总是想着问题的人，那么现在改变你的注意力。
The notion that education peaked around the time of the complainer's own graduation, and has gone down ever since, is an ancient one.
抱怨的人总是认为教育质量在自己毕业的时期达到巅峰而后盛极而衰，这古已有之。
Because the original complainer had posted full details of his experience, the company was able to contact the customer and rectify the situation.
因为这名用户将他所有的体验详细发布在网站上，企业可以直接和他取得联系并进行改进。
blog.sina.com.cn

Thanks to peer pressure, Leiserson was spared the indignity of cracking down on the complainer.
FORBES: Stanford MBA's Virtual Square for Student Q&A
If you are a complainer, and you are thinking of becoming an entrepreneur, think again.
FORBES: 9 Ways For Entrepreneurs To Counter Negative Vibes
If your message contains nothing but problems, you are nothing but a complainer.
FORBES: What Is Your Problem? -Media Training

A complainer is someone who complains a lot about their problems or about things they do not like.