摘要
Inthe13thcentury,MarcoPolotraveledalongwaytoChina.HewasafamousItalian1.DuringhisstayinChina,hesawmanywonderfulthings.Oneofthethingshe2wasthattheChineseusedpapermoney.Peoplein3countriesdidn’tusepapermoneyuntilthe17thcentury.However,peopleinChinabegantousepapermoneyinthe10thcentury.4wasinventedbyaChineseabout2,000yearsago.HisnamewasCaiLun.Hethen5thesepiecesofpapertogetherandmadethemintoa6.Nowpapermainlycomesfromtrees.Weuseiteveryday.Sometimeswewastealotofit.Ifwekeepondoingso,peoplehavetocutdownmanymoretrees.Thentherewillnotbeanytreesleft.Ifthereareno7,therewillbenopaper.
出版日期
2018年06月16日（中国期刊网平台首次上网日期，不代表论文的发表时间）
