太阳能
沼气池污水填料In its early days, before the invention of paper, people used tortoise shells, animal bones, gold and stone, bamboo slips, wood and cloth to record and remember things. People often call it the year when papermaking was invented. According to historical records, the invention of paper was reported to the Chinese emperor by Cai Lun, an official of the imperial court.However, according to recent archaeological investigations, the actual invention of papermaking was several years ago. It is obvious that the ancient paper pieces at Xuanquanzhi site in Dunhuang, Gansu Province, Northwest China, were made during the reign of Emperor Wu between BC and BC, regardless of Tailun Whether it is the real inventor of paper, he should be honored in China's history because he played a role in developing a material that made China's revolution. The invention of paper was a great contribution to China's civilization and world civilization.
压铸机料筒的设计
The supply of cheap paper meant that great thoughts could be written on paper and could b
蓝牙GPS
破碎机刀具e read quickly and widely by the advanced nature and new ideas of the readers. Pass it on to most people. It has promoted and accelerated the pace of human civilization and development.
促进剂nsThe invention of paper enriched culture and literature, produced more and more great works, and passed on to most people.
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