英語(yǔ)聽(tīng)力 學(xué)英語(yǔ),練聽(tīng)力,上聽(tīng)力課堂! 注冊(cè) 登錄
> 在線聽(tīng)力 > 英語(yǔ)高級(jí)聽(tīng)力 > 英語(yǔ)時(shí)差 >  第655篇

英語(yǔ)時(shí)差:造紙的化工過(guò)程(上)

所屬教程:英語(yǔ)時(shí)差

瀏覽:

2020年10月17日

手機(jī)版
掃描二維碼方便學(xué)習(xí)和分享
https://online2.tingclass.net/lesson/shi0529/10000/10183/655.mp3
https://image.tingclass.net/statics/js/2012
Most modern paper is made from trees, but that hasn’t always been the case. In fact, paper can be made from any form of cellulose that can be broken down into fibers. Because cellulose is what gives all plants their structure, most plants can be used to make paper. Since the Chinese produced the first true paper around the year 100 A.D., people have made paper with rags, old fishing nets, grass, tree bark, and a variety of other plants. To begin the process, the cellulose has to be boiled, beaten, or shredded into tiny fibers. The paper pulp, made up of those tiny fibers is then spread into sheets, pressed, and dried to make paper. To make strong paper, you need long fibers which is why the pulp has to be beaten instead of chopped. Beating the cellulose separates the fibers from each other, while leaving individual fibers intact.
用戶搜索

瘋狂英語(yǔ) 英語(yǔ)語(yǔ)法 新概念英語(yǔ) 走遍美國(guó) 四級(jí)聽(tīng)力 英語(yǔ)音標(biāo) 英語(yǔ)入門 發(fā)音 美語(yǔ) 四級(jí) 新東方 七年級(jí) 賴世雄 zero是什么意思福州市洋洽新村英語(yǔ)學(xué)習(xí)交流群

網(wǎng)站推薦

英語(yǔ)翻譯英語(yǔ)應(yīng)急口語(yǔ)8000句聽(tīng)歌學(xué)英語(yǔ)英語(yǔ)學(xué)習(xí)方法

  • 頻道推薦
  • |
  • 全站推薦
  • 推薦下載
  • 網(wǎng)站推薦