a piece / sheet of paper
一张纸
a roll of toilet paper
一卷卫生纸
hand in papers
交卷
sign papers
签署文件
What news is there in the paper this morning?
今天早晨的报纸上有什么新闻?
He is preparing a paper on world population.
他正在准备一篇关于世界人口的论文。