writing paper 是不可数的，例如：
1.The prisoners tried to barter with the guards for items like writing paper and books.囚犯们试着从看守那里换取稿纸和书之类的东西。
2.Most people assume that if you stop doing a task like answering emails or writing a paper, your brain will naturally recover, so that when you start again later in the day or the next morning, you'll have your energy back.大多数人会认为，如果你停止执行某项任务，如回复电子邮件或者写论文，你的大脑会自然而然地恢复，所以当你这一天的晚些时侯或者第二天早上再开始工作时，你就又变得精力充沛了。
3.Haas occupied himself in writing his research paper.哈斯忙于写他的调查报告。