Problem: Printed circuit board:

The reinforcement type defines two major classes of materials - woven and non-woven. Woven reinforcements are cheaper, but the high dielectric constant of glass may not be favorable for many higher-frequency applications. The spatially nonhomogeneous structure also introduces local variations in electrical parameters, due to different resin/glass ratio at different areas of the weave pattern. Nonwoven reinforcements, or materials with low or no reinforcement, are more expensive but more suitable for some RF/analog applications.

The reinforcement type defines which two minor classes of materials?
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A: unanswerable

Problem: In the medieval Islamic world, an elementary school was known as a maktab, which dates back to at least the 10th century. Like madaris (which referred to higher education), a maktab was often attached to an endowed mosque. In the 11th century, the famous Persian Islamic philosopher and teacher Ibn Sina (known as Avicenna in the West), in one of his books, wrote a chapter about the maktab entitled "The Role of the Teacher in the Training and Upbringing of Children," as a guide to teachers working at maktab schools. He wrote that children can learn better if taught in classes instead of individual tuition from private tutors, and he gave a number of reasons for why this is the case, citing the value of competition and emulation among pupils, as well as the usefulness of group discussions and debates. Ibn Sina described the curriculum of a maktab school in some detail, describing the curricula for two stages of education in a maktab school.
What's the third component of education from Ibn Sina?
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Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The PlayStation 3 Slim received extremely positive reviews as well as a boost in sales; less than 24 hours after its announcement, PS3 Slim took the number-one bestseller spot on Amazon.com in the video games section for fifteen consecutive days. It regained the number-one position again one day later. PS3 Slim also received praise from PC World giving it a 90 out of 100 praising its new repackaging and the new value it brings at a lower price as well as praising its quietness and the reduction in its power consumption. This is in stark contrast to the original PS3's launch in which it was given position number-eight on their "The Top 21 Tech Screwups of 2006" list.
For how many consecutive days did the PS4 Slim hold the number-one spot on Amazon.com?
A: unanswerable

Context and question: The number and variety of plants, animals and other organisms that exist is known as biodiversity. It is an essential component of nature and it ensures the survival of human species by providing food, fuel, shelter, medicines and other resources to mankind. The richness of biodiversity depends on the climatic conditions and area of the region. All species of plants taken together are known as flora and about 70,000 species of plants are known till date. All species of animals taken together are known as fauna which includes birds, mammals, fish, reptiles, insects, crustaceans, molluscs, etc.
What ensures the survival of human species by providing food, shelter, other resources to mankind?
Answer: biodiversity

Question: Back in Warsaw that year, Chopin heard Niccolo Paganini play the violin, and composed a set of variations, Souvenir de Paganini. It may have been this experience which encouraged him to commence writing his first Etudes, (182932), exploring the capacities of his own instrument. On 11 August, three weeks after completing his studies at the Warsaw Conservatory, he made his debut in Vienna. He gave two piano concerts and received many favourable reviewsin addition to some commenting (in Chopin's own words) that he was "too delicate for those accustomed to the piano-bashing of local artists". In one of these concerts, he premiered his Variations on La ci darem la mano, Op. 2 (variations on an aria from Mozart's opera Don Giovanni) for piano and orchestra. He returned to Warsaw in September 1829, where he premiered his Piano Concerto No. 2 in F minor, Op. 21 on 17 March 1830.
Is there an answer to this question: During what month did Frederic make his first appearance in Vienna?

Answer: August

QUES: By summer 1918, a million American soldiers, or "doughboys" as they were often called, of the American Expeditionary Forces were in Europe under the command of John J. Pershing, with 25,000 more arriving every week. The failure of Germany's spring offensive exhausted its reserves and they were unable to launch new offensives. The German Navy and home front then revolted and a new German government signed a conditional surrender, the Armistice, ending the war against the western front on November 11, 1918.

Who had overall command of the American forces in Europe?
What is the answer?
ANS:
John J. Pershing