Instructions: In this task, you're given a question, along with three passages, 1, 2, and 3. Your job is to determine which passage can be used to answer the question by searching for further information using terms from the passage. Indicate your choice as 1, 2, or 3.
Input: Question: How long had Britain had control of Hong Kong before returning it to China? Passage 1:The main road going through Wanstead is the A12 and was the site of a Roman villa, whilst Wanstead Manor was a Saxon and Norman manor. It formed part of the Municipal Borough of Wanstead and Woodford in Essex from 1937 until 1965, when Greater London was created. The area has a largely suburban feel, containing open grasslands such as Wanstead Flats, and the woodland of Wanstead Park, part of Epping Forest. The park, with artificial lakes, was formerly part of the estate of a large stately home Wanstead House, built by Richard Child, 1st Earl Tylney, one of the finest Palladian mansions in Britain and the architectural inspiration for Mansion House, London. It was subsequently demolished to pay the gambling debts of a relation of the Duke of Wellington.
 Passage 2:As a result of negotiations and the 1984 agreement between China and Britain, Hong Kong was returned to China and became its first Special Administrative Region on 1 July 1997, under the principle of "one country, two systems". Hong Kong has a different political system from mainland China. Hong Kong's independent judiciary functions under the common law framework. The Hong Kong Basic Law, the constitutional document drafted by the Chinese side before the handover based on the terms enshrined in the Joint Declaration, governs its political system, and stipulates that Hong Kong shall have a high degree of autonomy in all matters except foreign relations and military defence. The declaration stipulates that the region maintain its capitalist economic system and guarantees the rights and freedoms of its people for at least 50 years after the 1997 handover. The guarantees over the territory's autonomy and the individual rights and freedoms are enshrined in the Hong Kong Basic Law, which outlines the system of governance of the Hong Kong Special Administrative Region, but which is subject to the interpretation of the Standing Committee of the National People's Congress (NPCSC).
 Passage 3:He was born to Sir Christopher Ingold and Dr. Hilda Usherwood, and studied for a BSc in Chemistry at the University of London, completing his degree in 1949. He continued his higher education with a PhD in chemistry at Oxford University, which he completed in 1951. Soon after graduation he moved to Canada to begin work with the National Research Council, followed by two years of post-doctoral research at the University of British Columbia. He returned to work for the NRC in 1955 as a research officer, followed by a promotion to head of the Free Radical Chemistry Section. He was awarded the 1968 Petroleum Chemistry Award, the 1988 Linus Pauling Award, and both the Davy Medal and Royal Medal of the Royal Society, the latter for "elucidating the mechanism of reactions involving free radicals". In 1995 he was made an officer of the Order of Canada. He has received honorary degrees from the universities of Guelph, Mount Allison, St Andrews, Carleton, McMaster and Dalhousie.

Output:
2