Input: Read this: Heart disease, cancer, obesity, and diabetes are commonly called "Western" diseases because these maladies were once rarely seen in developing countries. An international study in China found some regions had virtually no cancer or heart disease, while in other areas they reflected "up to a 100-fold increase" coincident with shifts from diets that were found to be entirely plant-based to heavily animal-based, respectively. In contrast, diseases of affluence like cancer and heart disease are common throughout the developed world, including the United States. Adjusted for age and exercise, large regional clusters of people in China rarely suffered from these "Western" diseases possibly because their diets are rich in vegetables, fruits, and whole grains, and have little dairy and meat products. Some studies show these to be, in high quantities, possible causes of some cancers. There are arguments for and against this controversial issue.
Question: In which country was a study about the presence of cancer and heart disease in different regions done?

Output: China


Input: Read this: Green can communicate safety to proceed, as in traffic lights. Green and red were standardized as the colors of international railroad signals in the 19th century. The first traffic light, using green and red gas lamps, was erected in 1868 in front of the Houses of Parliament in London. It exploded the following year, injuring the policeman who operated it. In 1912, the first modern electric traffic lights were put up in Salt Lake City, Utah. Red was chosen largely because of its high visibility, and its association with danger, while green was chosen largely because it could not be mistaken for red. Today green lights universally signal that a system is turned on and working as it should. In many video games, green signifies both health and completed objectives, opposite red.
Question: When was the first modern traffic light put up in London?

Output: unanswerable


Input: Read this: Around 1200 BC, the Dorians, another Greek-speaking people, followed from Epirus. Traditionally, historians have believed that the Dorian invasion caused the collapse of the Mycenaean civilization, but it is likely the main attack was made by seafaring raiders (sea peoples) who sailed into the eastern Mediterranean around 1180 BC. The Dorian invasion was followed by a poorly attested period of migrations, appropriately called the Greek Dark Ages, but by 800 BC the landscape of Archaic and Classical Greece was discernible.
Question: What civilization is the group credited with starting?

Output: unanswerable


Input: Read this: The late Turrell V. Wylie, a former professor of the University of Washington, and Li Tieh-tseng argue that the reliability of the heavily censored History of Ming as a credible source on Sino-Tibetan relations is questionable, in the light of modern scholarship. Other historians also assert that these Ming titles were nominal and did not actually confer the authority that the earlier Yuan titles had. Van Praag writes that the "numerous economically motivated Tibetan missions to the Ming Court are referred to as 'tributary missions' in the Ming Shih." Van Praag writes that these "tributary missions" were simply prompted by China's need for horses from Tibet, since a viable horse market in Mongol lands was closed as a result of incessant conflict. Morris Rossabi also writes that "Tibet, which had extensive contacts with China during the Yuan, scarcely had diplomatic relations with the Ming."
Question: Who had a large amount of contacts with china during Yuan?

Output:
Tibet