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 The paper also before， oracle bones， bamboo slips and silk silk is used for writing， the ancient recorded 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 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 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 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 Code for the sale， made with bark and spacious cloth， net to make 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 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 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 Printing: is the working people in ancient China through long-term practice and research before the invention About the year before and after 600 years of Sui Dynasty， people from the engraved seal inspired， in the history of mankind's earliest invention of woodblock Woodblock printing is in a certain thickness of the smooth wood， paste copy neat manuscript， thin and almost transparent paper front and wood paste， the word became the body， strokes Engraving workers graver in the suites have writing section is cut away， is a convex embossed font， and font recessed beneath the different When printing， on a raised fonts with ink， and then the paper covering on top of it， gently wipe away the paper back， writing remain on the By the Song Dynasty， woodblock printing career development to the Woodblock printing on the spread of culture play an important role， but also has obvious The first version， time-consuming material costs， second， a large number of books stored inconveniently， third， is not easy to correct The Northern Song Dynasty civilian inventor Bi Sheng invented movable-type printing， woodblock printing these drawbacks Bi Sheng's Dynasty of an ordinary civilian intellectuals， the person He summed up the block printing of rich experience in practice， after repeated tests， the emperor Renzong of evolution years (AD 10411048 ) made the moveable， execute typesetting printing， completed the printing history of a major revolution， about 200 years later， this technology spread to other countries， the development of world civilization process to promote the role Gunpowder: is one of the four great inventions of Gunpowder， as the name suggests is the ( fire medicine ) Its origins and alchemy are closely related， Bachelor in ancient alchemy alchemy inadvertently It is a mixture of saltpeter， sulfur， carbon， and the top two in the Han Dynasty book into Chinese Materia Medica ( first classics of Shennong materia medica by ) have been listed as important medicinal Gunpowder itself is also come under the drug class， the Ming Dynasty Li Shizhen ( compendium of Materia Medica ) said， gunpowder can cure sore ringworm， insecticidal， provide moisture and The invention of gunpowder is a long-term alchemy pharmaceutical practice results， has been one thousand years of The Tang Dynasty， gunpowder has been used for The Song Dynasty， the war continuously， promote the accelerated development of gunpowder The government of the Northern Song Dynasty established a powder mill， has made gunpowder arrow， artillery and other combustion properties mainly weapons and ( bang cannon )， ( lightning bombs ) and other explosive strong The Southern Song Dynasty were created in 1259 to giant bamboo tube， built-in gunpowder ( sudden guns ) To the Yuan Dynasty and the emergence of bronze ( copper Fire Commission， known as the general) These are to gunpowder explosion as the driving force of arms， in the war revealed a hitherto unknown In 12， thirteenth Century， the gunpowder first introduced in Arabia state， and then spread to Greece and Europe and around the On the civilization and progress of human society， the economy and the development of science and culture， played a role in The law until the middle of the fourteenth Century， only then has the application of gunpowder and firearms Compass : the spring and Autumn period， Chinese working people in the mining， smelting， gradually recognized To the Warring States period， some people use magnets made apparatus to determine the direction， then called" compass"， it is in a along the plate placed on a water scoop like magnet， water scoop handle end of South To the late Northern Song Dynasty ( Eleventh Century AD)， the Chinese people have created artificial magnet， then created a" guide to the fish"， the " Fish" on the water surface， thus indicating the Later， after repeated research and improvement， and the magnetic steel sheet into a small magnetic needle， and makes its tip into the magnetic north pole， end become the south magnetic pole， which became a The Northern Song Dynasty， people create a suitable nautical compass， the maritime industry to a new During this period， China 's shipbuilding technology in the world the most At the beginning of the fourteenth Century， the compass was introduced into Europe from
Nowadays，INTERNET is so important that we can hardly do jobs without But every coin has 2 sides，INTERNET also has many The details are as On one hand，INTERNET has many We usually search information or send E-mails for study for it can rise the working Online-shopping is a new and convenient way to buy things so that it is also popular among the young So we can inferm that the INTERNER has a lot of On the other hand，INTERNET also has many poor Spending so many time on online games is almost the The result is that people may find they have less interest in the work and study and than getting in a poor Another aspect is that lacking the face-to-face communication，the chatting and trade on the INTERNET become less and less So we can inferm that INTERNET has many
