Hello! today we will read about 

Great Wall of China

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The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China to protect the Chinese states and empires against the raids and invasions of the various nomadic groups of the Eurasian Steppe. Several walls were being built as early as the 7th century bce;^[2] these, later joined together and made bigger and stronger, are now collectively referred to as the Great Wall.^[3]Especially famous is the wall built 220–206 bce by Qin Shi Huang, the first Emperor of China. Little of that wall remains. Since then, the Great Wall has on and off been rebuilt, maintained, and enhanced; the majority of the existing wall is from the Ming Dynasty.

Other purposes of the Great Wall have included border controls, allowing the imposition of duties on goods transported along the Silk Road, regulation or encouragement of trade and the control of immigration and emigration. Furthermore, the defensive characteristics of the Great Wall were enhanced by the construction of watch towers, troop barracks, garrison stations, signaling capabilities through the means of smoke or fire, and the fact that the path of the Great Wall also served as a transportation corridor.

The Great Wall stretches from Dandong in the east, to Lop Lake in the west, along an arc that roughly delineates the southern edge of Inner Mongolia. A comprehensive archaeological survey, using advanced technologies, has concluded that the Ming walls measure 8,850 km (5,500 mi).^[4] This is made up of 6,259 km (3,889 mi) sections of actual wall, 359 km (223 mi) of trenches and 2,232 km (1,387 mi) of natural defensive barriers such as hills and rivers.^[4] Another archaeological survey found that the entire wall with all of its branches measure out to be 21,196 km (13,171 mi).^[5]

Sorry, I may have translated misread. 對不起，我可能有翻譯誤讀。

中國的長城是一系列由石頭，磚，夯土，木材工事，和其他材料，通常沿著由東到西線在中國的歷史北部邊界建立保護中國國家和帝國對抗襲擊和歐亞草原的各種游牧民族的入侵。一些圍牆正在建設早在公元前7世紀; [2]這些，後來連成一起，做大做強，現在統稱為長城[3]特別有名的是建牆公元前220到206。由秦始皇，中國的第一個皇帝。小的牆依然存在。從那時起，長城已經打開和關閉了重建，維護和增強;大多數現存城牆是明朝的。

長城的其他用途還包括邊境管制，允許職務上沿絲綢之路，法規或鼓勵貿易和移民和移民的控制運輸的貨物徵收。此外，長城的防禦特性通過瞭望塔，部隊營房，駐軍站的建設得到加強，信令功能通過冒煙或起火，而事實的手段對長城的路徑還擔任了運輸通道。

在長城綿延從丹東在東部，以羅布泊湖西部，沿著一個弧形的大致勾畫內蒙古的南緣。一個全面的考古調查，採用先進技術，得出結論認為，明城牆測量8850公里（5500英里）。[4]這是由溝槽6259公里（3,889英里）的實際壁段359公里（223英里）和天然的防禦屏障，如山丘，河流2232公里（1387英里）。[4]另外一個考古調查發現，整面牆及其所有分支機構量出為21196公里（13171英里）。[5]