Input: Read this: The hole walls for boards with two or more layers can be made conductive and then electroplated with copper to form plated-through holes.  These holes electrically connect the conducting layers of the PCB. For multi-layer boards, those with three layers or more, drilling typically produces a smear of the high temperature decomposition products of bonding agent in the laminate system. Before the holes can be plated through, this smear must be removed by a chemical de-smear process, or by plasma-etch. The de-smear process ensures that a good connection is made to the copper layers when the hole is plated through. On high reliability boards a process called etch-back is performed chemically with a potassium permanganate based etchant or plasma. The etch-back removes resin and the glass fibers so that the copper layers extend into the hole and as the hole is plated become integral with the deposited copper.
Question: Smears are removed with a chemical smear what?

Output: unanswerable


QUES: Many species of birds are economically important. Domesticated and undomesticated birds (poultry and game) are important sources of eggs, meat, and feathers. Songbirds, parrots, and other species are popular as pets. Guano (bird excrement) is harvested for use as a fertilizer. Birds prominently figure throughout human culture. About 120–130 species have become extinct due to human activity since the 17th century, and hundreds more before then. Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational birdwatching is an important part of the ecotourism industry.

Which birds are popular as pets?
What is the answer?
ANS: Songbirds, parrots


QUES: With the deactivation of USS Enterprise in December 2012, the U.S. fleet comprises 10 supercarriers. The House Armed Services Seapower subcommittee on 24 July 2007, recommended seven or maybe eight new carriers (one every four years). However, the debate has deepened over budgeting for the $12–14.5 billion (plus $12 billion for development and research) for the 100,000 ton Gerald R. Ford-class carrier (estimated service 2016) compared to the smaller $2 billion 45,000 ton America-class amphibious assault ships, which are able to deploy squadrons of F-35Bs. The first of this class, USS America, is now in active service with another, USS Tripoli, under construction and 9 more are planned.
How many supercarriers did the U.N. fleet have following the deactivation of the USS Enterprise?

ANS: unanswerable


On 21 September, the Soviets and Germans signed a formal agreement coordinating military movements in Poland, including the "purging" of saboteurs. A joint German–Soviet parade was held in Lvov and Brest-Litovsk, while the countries commanders met in the latter location. Stalin had decided in August that he was going to liquidate the Polish state, and a German–Soviet meeting in September addressed the future structure of the "Polish region". Soviet authorities immediately started a campaign of Sovietization of the newly acquired areas. The Soviets organized staged elections, the result of which was to become a legitimization of Soviet annexation of eastern Poland.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Why did Soviets create fake elections in Poland?
Ah, so.. legitimization of Soviet annexation of eastern Poland


Question: In 2004, worldwide sales of audio CDs, CD-ROMs and CD-Rs reached about 30 billion discs. By 2007, 200 billion CDs had been sold worldwide. CDs are increasingly being replaced by other forms of digital storage and distribution, with the result that audio CD sales rates in the U.S. have dropped about 50% from their peak; however, they remain one of the primary distribution methods for the music industry. In 2014, revenues from digital music services matched those from physical format sales for the first time.
Try to answer this question if possible: Why are CD sales doing better than digital storage services?
Answer: unanswerable


Context and question: The government of India is based on a tiered system, in which the Constitution of India delineates the subjects on which each tier of government has executive powers. The Constitution originally provided for a two-tier system of government, the Union Government (also known as the Central Government), representing the Union of India, and the State governments. Later, a third tier was added in the form of Panchayats and Municipalities. In the current arrangement, The Seventh Schedule of the Indian Constitution delimits the subjects of each level of governmental jurisdiction, dividing them into three lists:
What isn't a tiered system? 
Answer:
unanswerable