Input: Read this: In the medieval Middle Eastern world, the physicist and Islamic scholar, Al-Farabi (Alpharabius, 872–950), conducted a small experiment concerning the existence of vacuum, in which he investigated handheld plungers in water.[unreliable source?] He concluded that air's volume can expand to fill available space, and he suggested that the concept of perfect vacuum was incoherent. However, according to Nader El-Bizri, the physicist Ibn al-Haytham (Alhazen, 965–1039) and the Mu'tazili theologians disagreed with Aristotle and Al-Farabi, and they supported the existence of a void. Using geometry, Ibn al-Haytham mathematically demonstrated that place (al-makan) is the imagined three-dimensional void between the inner surfaces of a containing body. According to Ahmad Dallal, Abū Rayhān al-Bīrūnī also states that "there is no observable evidence that rules out the possibility of vacuum". The suction pump later appeared in Europe from the 15th century.
Question: Al-Farabi concluded a perfect vacuum was incoherent using what?

Output: handheld plungers in water.


Input: Read this: Patents have been criticized in the developing world, as they are thought to reduce access to existing medicines. Reconciling patents and universal access to medicine would require an efficient international policy of price discrimination. Moreover, under the TRIPS agreement of the World Trade Organization, countries must allow pharmaceutical products to be patented. In 2001, the WTO adopted the Doha Declaration, which indicates that the TRIPS agreement should be read with the goals of public health in mind, and allows some methods for circumventing pharmaceutical monopolies: via compulsory licensing or parallel imports, even before patent expiration.
Question: What did the WTO Declaration do?

Output: unanswerable


Input: Read this: Rutherford centralized organizational control of the Watch Tower Society. In 1919, he instituted the appointment of a director in each congregation, and a year later all members were instructed to report their weekly preaching activity to the Brooklyn headquarters. At an international convention held at Cedar Point, Ohio, in September 1922, a new emphasis was made on house-to-house preaching. Significant changes in doctrine and administration were regularly introduced during Rutherford's twenty-five years as president, including the 1920 announcement that the Jewish patriarchs (such as Abraham and Isaac) would be resurrected in 1925, marking the beginning of Christ's thousand-year Kingdom. Disappointed by the changes, tens of thousands of defections occurred during the first half of Rutherford's tenure, leading to the formation of several Bible Student organizations independent of the Watch Tower Society, most of which still exist. By mid-1919, as many as one in seven of Russell-era Bible Students had ceased their association with the Society, and as many as two-thirds by the end of the 1920s.
Question: What was a new emphasis made on at the international convention?

Output: house-to-house preaching


Input: Read this: Due to extreme variation in elevation, great variation occurs in the climatic conditions of Himachal . The climate varies from hot and subhumid tropical in the southern tracts to, with more elevation, cold, alpine, and glacial in the northern and eastern mountain ranges. The state has areas like Dharamsala that receive very heavy rainfall, as well as those like Lahaul and Spiti that are cold and almost rainless. Broadly, Himachal experiences three seasons: summer, winter, and rainy season. Summer lasts from mid-April till the end of June and most parts become very hot (except in the alpine zone which experiences a mild summer) with the average temperature ranging from 28 to 32 °C (82 to 90 °F). Winter lasts from late November till mid March. Snowfall is common in alpine tracts (generally above 2,200 metres (7,218 ft) i.e. in the higher and trans-Himalayan region).
Question: How long does summer last?

Output:
mid-April till the end of June