Input: Cotton
In Iran (Persia), the history of cotton dates back to the Achaemenid era (5th century BC); however, there are few sources about the planting of cotton in pre-Islamic Iran. The planting of cotton was common in Merv, Ray and Pars of Iran. In Persian poets' poems, especially Ferdowsi's Shahname, there are references to cotton ("panbe" in Persian). Marco Polo (13th century) refers to the major products of Persia, including cotton. John Chardin, a French traveler of the 17th century who visited the Safavid Persia, spoke approvingly of the vast cotton farms of Persia.

What 13th century explorer saw cotton in Persia?
Output: Marco Polo

Input: History of science
Midway through the 19th century, the focus of geology shifted from description and classification to attempts to understand how the surface of the Earth had changed. The first comprehensive theories of mountain building were proposed during this period, as were the first modern theories of earthquakes and volcanoes. Louis Agassiz and others established the reality of continent-covering ice ages, and "fluvialists" like Andrew Crombie Ramsay argued that river valleys were formed, over millions of years by the rivers that flow through them. After the discovery of radioactivity, radiometric dating methods were developed, starting in the 20th century. Alfred Wegener's theory of "continental drift" was widely dismissed when he proposed it in the 1910s, but new data gathered in the 1950s and 1960s led to the theory of plate tectonics, which provided a plausible mechanism for it. Plate tectonics also provided a unified explanation for a wide range of seemingly unrelated geological phenomena. Since 1970 it has served as the unifying principle in geology.

What changed about the way geology was implemented during the 19th century?
Output: shifted from description and classification to attempts to understand how the surface of the Earth had changed

Input: Melbourne
Port Phillip is often warmer than the surrounding oceans and/or the land mass, particularly in spring and autumn; this can set up a "bay effect" similar to the "lake effect" seen in colder climates where showers are intensified leeward of the bay. Relatively narrow streams of heavy showers can often affect the same places (usually the eastern suburbs) for an extended period, while the rest of Melbourne and surrounds stays dry. Overall, Melbourne is, owing to the rain shadow of the Otway Ranges, nonetheless drier than average for southern Victoria. Within the city and surrounds, however, rainfall varies widely, from around 425 millimetres (17 in) at Little River to 1,250 millimetres (49 in) on the eastern fringe at Gembrook. Melbourne receives 48.6 clear days annually. Dewpoint temperatures in the summer range from 9.5 °C (49.1 °F) to 11.7 °C (53.1 °F).

Approximately how many sunny days does Melbourne receive annually?
Output: 48.6

Input: Napoleon
Napoleon could be considered one of the founders of modern Germany. After dissolving the Holy Roman Empire, he reduced the number of German states from 300 to less than 50, paving the way to German Unification. A byproduct of the French occupation was a strong development in German nationalism. Napoleon also significantly aided the United States when he agreed to sell the territory of Louisiana for 15 million dollars during the presidency of Thomas Jefferson. That territory almost doubled the size of the United States, adding the equivalent of 13 states to the Union.

How many German states remained after Napoleon reduced their numbers?
Output:
less than 50