Problem: As a teenager, he was greatly troubled by the Metaphysics of Aristotle, which he could not understand until he read al-Farabi's commentary on the work. For the next year and a half, he studied philosophy, in which he encountered greater obstacles. In such moments of baffled inquiry, he would leave his books, perform the requisite ablutions, then go to the mosque, and continue in prayer till light broke on his difficulties. Deep into the night, he would continue his studies, and even in his dreams problems would pursue him and work out their solution. Forty times, it is said, he read through the Metaphysics of Aristotle, till the words were imprinted on his memory; but their meaning was hopelessly obscure, until one day they found illumination, from the little commentary by Farabi, which he bought at a bookstall for the small sum of three dirhams. So great was his joy at the discovery, made with the help of a work from which he had expected only mystery, that he hastened to return thanks to God, and bestowed alms upon the poor.
How long did Avicenna study philosophy?
The answer is the following: year and a half

Much of the early paper made from wood pulp contained significant amounts of alum, a variety of aluminium sulfate salts that is significantly acidic. Alum was added to paper to assist in sizing, making it somewhat water resistant so that inks did not "run" or spread uncontrollably. Early papermakers did not realize that the alum they added liberally to cure almost every problem encountered in making their product would eventually be detrimental. The cellulose fibres that make up paper are hydrolyzed by acid, and the presence of alum would eventually degrade the fibres until the paper disintegrated in a process that has come to be known as "slow fire". Documents written on rag paper were significantly more stable. The use of non-acidic additives to make paper is becoming more prevalent, and the stability of these papers is less of an issue.
What acidic salts were commonly found in the early types of paper produced?
Alum

Input: Railway electrification system
Three-phase AC railway electrification was used in Italy, Switzerland and the United States in the early twentieth century. Italy was the major user, for lines in the mountainous regions of northern Italy from 1901 until 1976. The first lines were the Burgdorf-Thun line in Switzerland (1899), and the lines of the Ferrovia Alta Valtellina from Colico to Chiavenna and Tirano in Italy, which were electrified in 1901 and 1902. Other lines where the three-phase system were used were the Simplon Tunnel in Switzerland from 1906 to 1930, and the Cascade Tunnel of the Great Northern Railway in the United States from 1909 to 1927.

What country was a bigger user compare to the three of them?
Output: Italy

Input: Article: Another potential weapon system for anti-aircraft use is the laser. Although air planners have imagined lasers in combat since the late 1960s, only the most modern laser systems are currently reaching what could be considered "experimental usefulness". In particular the Tactical High Energy Laser can be used in the anti-aircraft and anti-missile role. If current developments continue, some[who?] believe it is reasonable to suggest that lasers will play a major role in air defence starting in the next ten years.

Now answer this question: When do some people believe that lasers can play a more prominent role in air defence?

Output: in the next ten years

Article: The Suez crisis and the choice of Eden's successor led in 1957 to the first major personal criticism of the Queen. In a magazine, which he owned and edited, Lord Altrincham accused her of being "out of touch". Altrincham was denounced by public figures and slapped by a member of the public appalled by his comments. Six years later, in 1963, Macmillan resigned and advised the Queen to appoint the Earl of Home as prime minister, advice that she followed. The Queen again came under criticism for appointing the prime minister on the advice of a small number of ministers or a single minister. In 1965, the Conservatives adopted a formal mechanism for electing a leader, thus relieving her of involvement.

Question: When was a formal mechanism for electing the Minister adopted?
Ans: 1965

Input: Eritrea
Traditional Eritrean attire is quite varied among the ethnic groups of Eritrea. In the larger cities, most people dress in Western casual dress such as jeans and shirts. In offices, both men and women often dress in suits. Traditional clothing for Christian Tigrinya-speaking highlanders consists of bright white gowns called zurias for the women, and long white shirts accompanied by white pants for the men. In Muslim communities in the Eritrean lowland, the women traditionally dress in brightly colored clothes. Only Rashaida women maintain a tradition of covering half of their faces, though they do not cover their hair.

Who are the only women who follow the tradition of covering half of their faces, though not their hair?
Output:
Rashaida women