Input: Article: From his diagrams of a small number of particles interacting in spacetime, Feynman could then model all of physics in terms of the spins of those particles and the range of coupling of the fundamental forces. Feynman attempted an explanation of the strong interactions governing nucleons scattering called the parton model. The parton model emerged as a complement to the quark model developed by his Caltech colleague Murray Gell-Mann. The relationship between the two models was murky; Gell-Mann referred to Feynman's partons derisively as "put-ons". In the mid-1960s, physicists believed that quarks were just a bookkeeping device for symmetry numbers, not real particles, as the statistics of the Omega-minus particle, if it were interpreted as three identical strange quarks bound together, seemed impossible if quarks were real. The Stanford linear accelerator deep inelastic scattering experiments of the late 1960s showed, analogously to Ernest Rutherford's experiment of scattering alpha particles on gold nuclei in 1911, that nucleons (protons and neutrons) contained point-like particles that scattered electrons. It was natural to identify these with quarks, but Feynman's parton model attempted to interpret the experimental data in a way that did not introduce additional hypotheses. For example, the data showed that some 45% of the energy momentum was carried by electrically-neutral particles in the nucleon. These electrically-neutral particles are now seen to be the gluons that carry the forces between the quarks and carry also the three-valued color quantum number that solves the Omega-minus problem. Feynman did not dispute the quark model; for example, when the fifth quark was discovered in 1977, Feynman immediately pointed out to his students that the discovery implied the existence of a sixth quark, which was discovered in the decade after his death.

Now answer this question: What model did Murray Gell-Mann develop?

Output: quark model

Input: Article: The National Autonomous University of Mexico (UNAM), located in Mexico City, is the largest university on the continent, with more than 300,000 students from all backgrounds. Three Nobel laureates, several Mexican entrepreneurs and most of Mexico's modern-day presidents are among its former students. UNAM conducts 50% of Mexico's scientific research and has presence all across the country with satellite campuses, observatories and research centres. UNAM ranked 74th in the Top 200 World University Ranking published by Times Higher Education (then called Times Higher Education Supplement) in 2006, making it the highest ranked Spanish-speaking university in the world. The sprawling main campus of the university, known as Ciudad Universitaria, was named a World Heritage Site by UNESCO in 2007.

Now answer this question: What worldwide ranking does UNAM hold?

Output: 74th

Input: Article: Nanjing's airport, Lukou International Airport, serves both national and international flights. In 2013, Nanjing airport handled 15,011,792 passengers and 255,788.6 tonnes of freight. The airport currently has 85 routes to national and international destinations, which include Japan, Korea, Thailand, Malaysia, Singapore, USA and Germany. The airport is connected by a 29-kilometre (18 mi) highway directly to the city center, and is also linked to various intercity highways, making it accessible to the passengers from the surrounding cities. A railway Ninggao Intercity Line is being built to link the airport with Nanjing South Railway Station. Lukou Airport was opened on 28 June 1997, replacing Nanjing Dajiaochang Airport as the main airport serving Nanjing. Dajiaochang Airport is still used as a military air base.

Now answer this question: When did the airport open for business?

Output:
28 June 1997