Question: Where does the great wall of the country producing the most cotton in the world end?

full_context: Document 1: Nanjing: Nanjing is the intersection of Yangtze River, an east-west water transport artery, and Nanjing–Beijing railway, a south-north land transport artery, hence the name “door of the east and west, throat of the south and north”. Furthermore, the west part of the Ningzhen range is in Nanjing; the Loong-like Zhong Mountain is curling in the east of the city; the tiger-like Stone Mountain is crouching in the west of the city, hence the name “the Zhong Mountain, a dragon curling, and the Stone Mountain, a tiger crouching”. Mr. Sun Yet-sen spoke highly of Nanjing in the “Constructive Scheme for Our Country”, “The position of Nanjing is wonderful since mountains, lakes and plains all integrated in it. It is hard to find another city like this.”
Document 2: Cotton: Current estimates for world production are about 25 million tonnes or 110 million bales annually, accounting for 2.5% of the world's arable land. China is the world's largest producer of cotton, but most of this is used domestically. The United States has been the largest exporter for many years. In the United States, cotton is usually measured in bales, which measure approximately 0.48 cubic meters (17 cubic feet) and weigh 226.8 kilograms (500 pounds).
Document 3: Great Wall of China: 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 BC; these, later joined together and made bigger and stronger, are collectively referred to as the Great Wall. Especially famous is the wall built in 220 -- 206 BC by Qin Shi Huang, the first Emperor of China. Little of that wall remains. The Great Wall has been rebuilt, maintained, and enhanced over various dynasties; the majority of the existing wall is from the Ming Dynasty (1368 -- 1644).
Document 4: Great Wall of China: 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). 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. Another archaeological survey found that the entire wall with all of its branches measure out to be 21,196 km (13,171 mi). Today, the Great Wall is generally recognized as one of the most impressive architectural feats in history.
Document 5: Great Wall of China: Great Wall of China 萬里長城 The Great Wall of China at Jinshanling Map of all the wall constructions General information Type Fortification Country China Coordinates 40 ° 41 ′ N 117 ° 14 ′ E ﻿ / ﻿ 40.68 ° N 117.23 ° E ﻿ / 40.68; 117.23 Coordinates: 40 ° 41 ′ N 117 ° 14 ′ E ﻿ / ﻿ 40.68 ° N 117.23 ° E ﻿ / 40.68; 117.23 Technical details Size 21,196 km (13,171 mi) UNESCO World Heritage Site Criteria Cultural: (i), (ii), (iii), (iv), (vi) Reference 438 Inscription 1987 (11th Session) (edit on Wikidata)
Document 6: Great Wall of China: One of the most striking sections of the Ming Great Wall is where it climbs extremely steep slopes in Jinshanling. There it runs 11 km (7 mi) long, ranges from 5 to 8 m (16 ft 5 in to 26 ft 3 in) in height, and 6 m (19 ft 8 in) across the bottom, narrowing up to 5 m (16 ft 5 in) across the top. Wangjinglou (t 望京樓, s 望京楼, Wàngjīng Lóu) is one of Jinshanling's 67 watchtowers, 980 m (3,220 ft) above sea level. Southeast of Jinshanling is the Mutianyu Great Wall which winds along lofty, cragged mountains from the southeast to the northwest for 2.25 km (1.40 mi). It is connected with Juyongguan Pass to the west and Gubeikou to the east. This section was one of the first to be renovated following the turmoil of the Cultural Revolution.
Document 7: Cotton: The largest producers of cotton, currently (2009), are China and India, with annual production of about 34 million bales and 33.4 million bales, respectively; most of this production is consumed by their respective textile industries. The largest exporters of raw cotton are the United States, with sales of $4.9 billion, and Africa, with sales of $2.1 billion. The total international trade is estimated to be $12 billion. Africa's share of the cotton trade has doubled since 1980. Neither area has a significant domestic textile industry, textile manufacturing having moved to developing nations in Eastern and South Asia such as India and China. In Africa, cotton is grown by numerous small holders. Dunavant Enterprises, based in Memphis, Tennessee, is the leading cotton broker in Africa, with hundreds of purchasing agents. It operates cotton gins in Uganda, Mozambique, and Zambia. In Zambia, it often offers loans for seed and expenses to the 180,000 small farmers who grow cotton for it, as well as advice on farming methods. Cargill also purchases cotton in Africa for export.
Document 8: Mausoleum of the First Qin Emperor: The Mausoleum of the First Qin Emperor (Qin Shi Huang) () is located in Lintong District, Xi'an, Shaanxi province of China. This mausoleum was constructed over 38 years, from 246 to 208 BC, and is situated underneath a 76-meter-tall tomb mound shaped like a truncated pyramid. The layout of the mausoleum is modeled on the Qin capital Xianyang, divided into inner and outer cities. The circumference of the inner city is 2.5 km (1.55 miles) and the outer is 6.3 km (3.9 miles). The tomb is located in the southwest of the inner city and faces east. The main tomb chamber housing the coffin and burial artifacts is the core of the architectural complex of the mausoleum.
Document 9: Cotton production in the United States: Texas produces more cotton than any other state in the United States. With eight production regions around Texas, and only four geographic regions, it is the state's leading cash crop. Texas produces approximately 25% of the country's cotton crop on more than 6 million acres, the equivalent of over 9,000 square miles (23,000 km) of cotton fields. Texas Cotton Producers includes nine certified cotton grower organizations; it addresses national and statewide cotton grower issues, such as the national farm bill and environmental legislation.
Document 10: Shanhai Pass: Located south of Yan Mountain, and north of the Bohai Sea, for centuries the pass guarded the narrow passage between Northeast and Central East China. Both the Northern Qi Dynasty and the Tang Dynasty constructed passes here. In 1381, Ming general Xu Da constructed the present pass, which was named Shanhaiguan (literally "mountain-sea-pass") because of its position between the mountains and the sea. In the late 16th century, Ming general Qi Jiguang began fortification and construction of a military city around the pass, building cities and forts to the east, south and north, making it one of the most heavily fortified passes in China. Today it is one of the best preserved passes in the Great Wall.
Document 11: Great Wall of China: 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 with an eye to expansion. Several walls were being built as early as the 7th century BC; these, later joined together and made bigger and stronger, are collectively referred to as the Great Wall. Especially famous is the wall built in 220 -- 206 BC by Qin Shi Huang, the first Emperor of China. Little of that wall remains. The Great Wall has been rebuilt, maintained, and enhanced over various dynasties; the majority of the existing wall is from the Ming Dynasty (1368 -- 1644).
Document 12: Agriculture in China: Although China's agricultural output is the largest in the world, only about 15% of its total land area can be cultivated. China's arable land, which represents 10% of the total arable land in the world, supports over 20% of the world's population. Of this approximately 1.4 million square kilometers of arable land, only about 1.2% (116,580 square kilometers) permanently supports crops and 525,800 square kilometers are irrigated. The land is divided into approximately 200 million households, with an average land allocation of just 0.65 hectares (1.6 acres).
Document 13: Cotton: Successful cultivation of cotton requires a long frost-free period, plenty of sunshine, and a moderate rainfall, usually from 600 to 1,200 mm (24 to 47 in). Soils usually need to be fairly heavy, although the level of nutrients does not need to be exceptional. In general, these conditions are met within the seasonally dry tropics and subtropics in the Northern and Southern hemispheres, but a large proportion of the cotton grown today is cultivated in areas with less rainfall that obtain the water from irrigation. Production of the crop for a given year usually starts soon after harvesting the preceding autumn. Cotton is naturally a perennial but is grown as an annual to help control pests. Planting time in spring in the Northern hemisphere varies from the beginning of February to the beginning of June. The area of the United States known as the South Plains is the largest contiguous cotton-growing region in the world. While dryland (non-irrigated) cotton is successfully grown in this region, consistent yields are only produced with heavy reliance on irrigation water drawn from the Ogallala Aquifer. Since cotton is somewhat salt and drought tolerant, this makes it an attractive crop for arid and semiarid regions. As water resources get tighter around the world, economies that rely on it face difficulties and conflict, as well as potential environmental problems. For example, improper cropping and irrigation practices have led to desertification in areas of Uzbekistan, where cotton is a major export. In the days of the Soviet Union, the Aral Sea was tapped for agricultural irrigation, largely of cotton, and now salination is widespread.
Document 14: Cotton: Cotton remains a major export of the southern United States, and a majority of the world's annual cotton crop is of the long - staple American variety.
Document 15: Cotton: The 25,000 cotton growers in the United States of America are heavily subsidized at the rate of $2 billion per year although China now provides the highest overall level of cotton sector support. The future of these subsidies is uncertain and has led to anticipatory expansion of cotton brokers' operations in Africa. Dunavant expanded in Africa by buying out local operations. This is only possible in former British colonies and Mozambique; former French colonies continue to maintain tight monopolies, inherited from their former colonialist masters, on cotton purchases at low fixed prices.
ground_truth: Lop Lake in the west
sub_queries: who produces the most cotton in the world Answer: China
where does the great wall of China end Answer: Lop Lake in the west