Question: Who was the first European to reach the country to which Curtiss P-36 Hawk was sold first?

full_context: Document 1: Han dynasty: Even before Han's expansion into Central Asia, diplomat Zhang Qian's travels from 139 to 125 BC had established Chinese contacts with many surrounding civilizations. Zhang encountered Dayuan (Fergana), Kangju (Sogdiana), and Daxia (Bactria, formerly the Greco-Bactrian Kingdom); he also gathered information on Shendu (Indus River valley of North India) and Anxi (the Parthian Empire). All of these countries eventually received Han embassies. These connections marked the beginning of the Silk Road trade network that extended to the Roman Empire, bringing Han items like silk to Rome and Roman goods such as glasswares to China.
Document 2: Xian H-6: Delivery of the Tu-16 to China began in 1958, and the Xi'an Aircraft Industrial Corporation (XAC) signed a licence production agreement with the USSR to build the type in the late 1950s. The first Chinese Tu-16, or "H-6" as it was designated in Chinese service, flew in 1959. Production was performed by the plant at Xian, with at least 150 built into the 1990s. China is estimated to currently operate around 120 of the aircraft.
Document 3: Nanjing: As the center of the empire, early-Ming Nanjing had worldwide connections. It was home of the admiral Zheng He, who went to sail the Pacific and Indian Oceans, and it was visited by foreign dignitaries, such as a king from Borneo (Boni 渤泥), who died during his visit to China in 1408. The Tomb of the King of Boni, with a spirit way and a tortoise stele, was discovered in Yuhuatai District (south of the walled city) in 1958, and has been restored.
Document 4: Chronology of European exploration of Asia: A Roman diplomat or merchant lands in northern Vietnam and visits Nanjing, China and the court of Sun Quan, ruler of Eastern Wu
Document 5: History of Vietnam: After Quang Trung's death, the Tây Sơn dynasty became unstable as the remaining brothers fought against each other and against the people who were loyal to Nguyễn Huệ's infant son. Nguyễn Ánh sailed north in 1799, capturing Tây Sơn's stronghold Qui Nhơn. In 1801, his force took Phú Xuân, the Tây Sơn capital. Nguyễn Ánh finally won the war in 1802, when he sieged Thăng Long (Hanoi) and executed Nguyễn Huệ's son, Nguyễn Quang Toản, along with many Tây Sơn generals and officials. Nguyễn Ánh ascended the throne and called himself Emperor Gia Long. Gia is for Gia Định, the old name of Saigon; Long is for Thăng Long, the old name of Hanoi. Hence Gia Long implied the unification of the country. The Nguyễn dynasty lasted until Bảo Đại's abdication in 1945. As China for centuries had referred to Đại Việt as Annam, Gia Long asked the Manchu Qing emperor to rename the country, from Annam to Nam Việt. To prevent any confusion of Gia Long's kingdom with Triệu Đà's ancient kingdom, the Manchu emperor reversed the order of the two words to Việt Nam. The name Vietnam is thus known to be used since Emperor Gia Long's reign. Recently historians have found that this name had existed in older books in which Vietnamese referred to their country as Vietnam.
Document 6: ZB-53: The ZB-53 was designed by Václav Holek and Miroslav Rolčík of the Zbrojovka Brno works as a replacement for the Schwarzlose machine gun of World War I origin. Based on the earlier vz. 35 machine gun, the prototype was tested in 1936 and the following year the new machine gun was adopted by the Czechoslovak Army with the designation TK vz. 37 ("Heavy Machine Gun Mark 1937"). It was introduced as the standard machine gun of Czechoslovak LT-35 and LT-38 tanks. Czechoslovakia exported the gun to Romania, Yugoslavia, Argentina, Afghanistan, Iran and China (large numbers used during the Second Sino-Japanese War), while UK bought a license and started to produce its own version, known as the Besa machine gun (over 60,000 pieces made). During the German occupation of the factory, large numbers were produced for the Waffen-SS until 1942.
Document 7: Lockheed P-38 Lightning: Lockheed proposed a carrier-based Model 822 version of the Lightning for the United States Navy. The Model 822 would have featured folding wings, an arresting hook, and stronger undercarriage for carrier operations. The navy was not interested, as they regarded the Lightning as too big for carrier operations and did not like liquid-cooled engines anyway, and the Model 822 never went beyond the paper stage. However, the navy did operate four land-based F-5Bs in North Africa, inherited from the USAAF and redesignated FO-1.
Document 8: Han dynasty: The Xiongnu, a nomadic steppe confederation, defeated the Han in 200 BC and forced the Han to submit as a de facto inferior partner, but continued their raids on the Han borders. Emperor Wu of Han (r. 141–87 BC) launched several military campaigns against them. The ultimate Han victory in these wars eventually forced the Xiongnu to accept vassal status as Han tributaries. These campaigns expanded Han sovereignty into the Tarim Basin of Central Asia, divided the Xiongnu into two separate confederations, and helped establish the vast trade network known as the Silk Road, which reached as far as the Mediterranean world. The territories north of Han's borders were quickly overrun by the nomadic Xianbei confederation. Emperor Wu also launched successful military expeditions in the south, annexing Nanyue in 111 BC and Dian in 109 BC, and in the Korean Peninsula where the Xuantu and Lelang Commanderies were established in 108 BC.
Document 9: Grumman: During World War II, Grumman became known for its "Cats", Navy fighter aircraft, F4F Wildcat and F6F Hellcat, and the less well known Grumman F7F Tigercat and Grumman F8F Bearcat (neither of which saw combat during World War II), and for its torpedo bomber TBF Avenger. Grumman ranked 22nd among United States corporations in the value of wartime production contracts. Grumman's first jet aircraft was the F9F Panther; it was followed by the upgraded F9F/F-9 Cougar, and the less well known F-11 Tiger in the 1950s. The company's big postwar successes came in the 1960s with the A-6 Intruder and E-2 Hawkeye and in the 1970s with the Grumman EA-6B Prowler and F-14 Tomcat. Grumman products were prominent in the films The Final Countdown, Top Gun and numerous World War II naval and Marine Corps aviation films. The U.S. Navy still employs the Hawkeye as part of Carrier Air Wings on board aircraft carriers, while the U.S. Marine Corps, the last branch of service to fly the Prowler retired it on March 8, 2019.
Document 10: China's Wings: China's Wings: War, Intrigue, Romance and Adventure in the Middle Kingdom during the Golden Age of Flight is a 2012 book by Gregory Crouch, published by Bantam Books. The book discusses the history of the China National Aviation Corporation (CNAC) and is focused on William Langhorne Bond as the central character. Harry Eagar of the "Maui News" stated that "is largely a biography of Bond." The book also describes Moon Fun Chin, a Chinese-American who rose from peasant roots, to become a lead CNAC pilot and finally to owning his own airline. Among other events, the book discusses the establishment of the first airline in China, the Second Sino-Japanese War, "The Hump" airlift, and the 1938 Kweilin incident. The book ends after the 1949 Communist takeover.
Document 11: Curtiss P-36 Hawk: Internal company designation for a simplified export version with fixed landing gear, two slightly differing aircraft built, first sold to China, second to Argentina
Document 12: Cessna 172: The Cessna 172 Skyhawk is an American four - seat, single - engine, high wing, fixed - wing aircraft made by the Cessna Aircraft Company. First flown in 1955, more 172s have been built than any other aircraft.
Document 13: France–Vietnam relations: French -- Vietnamese relations started as early as the 17th century with the mission of the Jesuit father Alexandre de Rhodes. Various traders would visit Vietnam during the 18th century, until the major involvement of French forces under Pigneau de Béhaine from 1787 to 1789 helped establish the Nguyễn Dynasty. France was heavily involved in Vietnam in the 19th century under the pretext of protecting the work of Catholic missionaries in the country. France progressively carved for itself a huge colony, which would form French Indochina in 1887. France continued to rule Vietnam as a colony until France's defeat in the First Indochina War and the proclamation of Vietnam's independence in 1954.
Document 14: Curtiss Eagle: The Curtiss Eagle (retroactively designated the Model 19 by Curtiss some years later) was an airliner produced in small numbers in the United States shortly after World War I. The aircraft was a conventional biplane with three-bay, unstaggered wings of equal span. The fuselage was a very advanced design for its day, incorporating careful streamlining of its monocoque structure, and offering the crew as well as the passengers a fully enclosed cabin. The Eagle is sometimes named as the first American tri-motor aircraft; however Curtiss' own Model H flying boat flew with three engines for a time in 1914 before being converted back to twin-engine configuration.
Document 15: Yuan dynasty: The first recorded travels by Europeans to China and back date from this time. The most famous traveler of the period was the Venetian Marco Polo, whose account of his trip to "Cambaluc," the capital of the Great Khan, and of life there astounded the people of Europe. The account of his travels, Il milione (or, The Million, known in English as the Travels of Marco Polo), appeared about the year 1299. Some argue over the accuracy of Marco Polo's accounts due to the lack of mentioning the Great Wall of China, tea houses, which would have been a prominent sight since Europeans had yet to adopt a tea culture, as well the practice of foot binding by the women in capital of the Great Khan. Some suggest that Marco Polo acquired much of his knowledge through contact with Persian traders since many of the places he named were in Persian.
ground_truth: A Roman diplomat or merchant
sub_queries: What country was sold to first? Answer: China
who was the first european to reach China Answer: A Roman diplomat or merchant