Problem: Mammal:

In an influential 1988 paper, Timothy Rowe defined Mammalia phylogenetically as the crown group mammals, the clade consisting of the most recent common ancestor of living monotremes (echidnas and platypuses) and therian mammals (marsupials and placentals) and all descendants of that ancestor. Since this ancestor lived in the Jurassic period, Rowe's definition excludes all animals from the earlier Triassic, despite the fact that Triassic fossils in the Haramiyida have been referred to the Mammalia since the mid-19th century.

In what period did mammals live?
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A: unanswerable

Problem: Within the past ten years, the amount of social networking sites available to the public has greatly increased as well as the number of adolescents using them. Several sources report a high proportion of adolescents who use social media: 73% of 1217 year olds reported having at least one social networking profile; two-thirds (68%) of teens text every day, half (51%) visit social networking sites daily, and 11% send or receive tweets at least once every day. In fact, more than a third (34%) of teens visit their main social networking site several times a day. One in four (23%) teens are "heavy" social media users, meaning they use at least two different types of social media each and every day.
In recent years, has the amount of social networking sites available to the public increased or decreased?
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Answer: greatly increased

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
In 2009 Tajikistan had 26 airports, 18 of which had paved runways, of which two had runways longer than 3,000 meters. The country's main airport is Dushanbe International Airport which as of April 2015, had regularly scheduled flights to major cities in Russia, Central Asia, as well as Delhi, Dubai, Frankfurt, Istanbul, Kabul, Tehran, and Urumqi amongst others. There are also international flights, mainly to Russia, from Khujand Airport in the northern part of the country as well as limited international services from Kulob Airport, and Qurghonteppa International Airport. Khorog Airport is a domestic airport and also the only airport in the sparsely populated eastern half of the country.
In 2019, Tajikistan had how many airports?
A: unanswerable

Context and question: Another non-obligate symbiosis is known from encrusting bryozoans and hermit crabs that live in a close relationship. The bryozoan colony (Acanthodesia commensale) develops a cirumrotatory growth and offers the crab (Pseudopagurus granulimanus) a helicospiral-tubular extension of its living chamber that initially was situated within a gastropod shell.
What species of crab has a helicospiral-tubular extension of its living chamber?
Answer: unanswerable

Question: In 1853, Victoria gave birth to her eighth child, Leopold, with the aid of the new anaesthetic, chloroform. Victoria was so impressed by the relief it gave from the pain of childbirth that she used it again in 1857 at the birth of her ninth and final child, Beatrice, despite opposition from members of the clergy, who considered it against biblical teaching, and members of the medical profession, who thought it dangerous. Victoria may have suffered from post-natal depression after many of her pregnancies. Letters from Albert to Victoria intermittently complain of her loss of self-control. For example, about a month after Leopold's birth Albert complained in a letter to Victoria about her "continuance of hysterics" over a "miserable trifle".
Is there an answer to this question: What was a new anaesthetic being used for childbirth in Victoria's time?

Answer: chloroform

Question: The Bronx is home to several Off-Off-Broadway theaters, many staging new works by immigrant playwrights from Latin America and Africa. The Pregones Theater, which produces Latin American work, opened a new 130-seat theater in 2005 on Walton Avenue in the South Bronx. Some artists from elsewhere in New York City have begun to converge on the area, and housing prices have nearly quadrupled in the area since 2002. However rising prices directly correlate to a housing shortage across the city and the entire metro area.
Is there an answer to this question: Where are many of the Bronx's playwrights from?

Answer:
Latin America and Africa