有关中国四大发明的英语短篇作文

The four great inventionsPaper: paper is an important chemical processes, the invention of paper is Chinese in the spread of human culture and development make a valuable contribution, is China's chemical history of a major achievement.The paper also before, oracle bones, bamboo slips and silk silk is used for writing, the ancient recorded material. But due to the rapid development of the economy, culture, bones and bamboo can not meet the demand of development, thus contributing to the improvement of writing tools. At that time people began using small silk made of paper, as the ancient Chinese when paper by hemp thread and silk, and preparation method of rough paper, so the quality is not so good. But the hemp thread and silk has its own role, to use them as a raw material for paper-making, would be greatly restricted, and difficult to get rapid development, to meet the cultural life of the requirement to paper.In the new situation request, Cai Lun of Eastern Han Dynasty for the emergence of papermaking to bring new breakthrough in the Eastern Han Dynasty," views on" 2 records:" Cai Lun, talented, dedicated to cautious, every vacation, closed to the guest, aeration body field. Code for the sale, made with bark and spacious cloth, net to make paper. Xing Yuan first year playing, the emperor can, since is not used, the salty called Cai Hou paper". From above, Cai Lun is using bark, rags, net of papermaking. Although before Cai Lun also has a paper, but raw material itself is very limited, and Cai Lun on the new raw materials, to solve this problem. Because the rag, broken fishnet had already finished their task, a waste and used as a raw material for papermaking industry, which plays an important role.Printing: is the working people in ancient China through long-term practice and research before the invention of. About the year before and after 600 years of Sui Dynasty, people from the engraved seal inspire 四大发明 造纸术:造纸是一项重要的化学工艺，纸的发明是中国在人类文化的传播和发展上所做出的一项十分宝贵的贡献，是中国化学史上的一项重大的成就。 在纸还未发明之前，甲骨、竹简和绢帛是古代用来供书写、记载的材料。但由于西汉的经济、文化迅速发展，甲骨和竹简不能满足发展的需求，从而促使了书写工具的改进。当时人们已开始应用小块的丝绵制成的纸，由于古汉时的纸张是由麻缕和丝绵，加上制法粗糙，所以纸张的质量不太好。而麻缕和丝绵都有其本身的作用，如要把它们用作造纸的原料，就必然会受到很大的限制，而难以得到迅速的发展，来满足文化生活上对纸张的要求。 在新的客观形势要求下，东汉蔡伦的出现为造纸术带来新突破，在《东汉观记》卷二上记载：“蔡伦，有才学，尽忠重慎，每次休沐，闭门以绝宾客，曝体田野。典作尚方，造意用树皮及敝布、鱼网作纸。元兴元年奏上，帝善其能，自是莫不用，天下咸称蔡侯纸”。从以上看来，蔡伦是用树皮、破布、鱼网造纸的。虽然在蔡伦之前也有纸的存在，但是原料本身就有很大的局限，而蔡伦对新原料的发现，解决了这个问题。因为破布、破鱼网早已结束了它们本身的任务，成了废物而又用作做原料，对造纸工业起了极大的推动作用。

火药Gunpowder

造纸术Papermaking

指南针Compass

印刷术Printing

只有造纸术是蔡伦改进的 其他没有具体发明人 一代代来的 年代更不用说了 像火药就是道士炼丹弄出来的 你这找谁说理去~

有利的爱迪生电灯

Edison

Electric bulb

袁隆平 杂交水稻 Hybrid Rice初高中物理生物书上很多

不利的 塑料袋Plastic bag

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