Question: Technically, all these coins are still legal tender at face value, though some are far more valuable today for their numismatic value, and for gold and silver coins, their precious metal value. From 1965 to 1970 the Kennedy half dollar was the only circulating coin with any silver content, which was removed in 1971 and replaced with cupronickel. However, since 1992, the U.S. Mint has produced special Silver Proof Sets in addition to the regular yearly proof sets with silver dimes, quarters, and half dollars in place of the standard copper-nickel versions. In addition, an experimental $4.00 (Stella) coin was also minted in 1879, but never placed into circulation, and is properly considered to be a pattern rather than an actual coin denomination.
Is there an answer to this question: What are non copper and nickel coins  valuable for?

Answer: unanswerable


Question: As a result of continued warming, the polar ice caps melted and much of Gondwana became a desert. In Eastern Antarctica, seed ferns or pteridosperms became abundant and large amounts of sandstone and shale were laid down at this time. Synapsids, commonly known as "mammal-like reptiles", were common in Antarctica during the Early Triassic and included forms such as Lystrosaurus. The Antarctic Peninsula began to form during the Jurassic period (206–146 Ma), and islands gradually rose out of the ocean. Ginkgo trees, conifers, bennettites, horsetails, ferns and cycads were plentiful during this period. In West Antarctica, coniferous forests dominated through the entire Cretaceous period (146–66 Ma), though southern beech became more prominent towards the end of this period. Ammonites were common in the seas around Antarctica, and dinosaurs were also present, though only three Antarctic dinosaur genera (Cryolophosaurus and Glacialisaurus, from the Hanson Formation, and Antarctopelta) have been described to date. It was during this era that Gondwana began to break up.
Is there an answer to this question: What caused polar ice caps to form on Gondwana?

Answer: unanswerable


Question: The Palácio da Alvorada is the official residence of the President of Brazil. The palace was designed, along with the rest of the city of Brasília, by Oscar Niemeyer and inaugurated in 1958. One of the first structures built in the republic's new capital city, the "Alvorada" lies on a peninsula at the margins of Lake Paranoá. The principles of simplicity and modernity, that in the past characterized the great works of architecture, motivated Niemeyer. The viewer has an impression of looking at a glass box, softly landed on the ground with the support of thin external columns. The building has an area of 7,000 m2 with three floors consisting of the basement, landing, and second floor. The auditorium, kitchen, laundry, medical center, and administration offices are at basement level. The rooms used by the presidency for official receptions are on the landing. The second floor has four suites, two apartments, and various private rooms which make up the residential part of the palace. The building also has a library, a heated Olympic-sized swimming pool, a music room, two dining rooms and various meeting rooms. A chapel and heliport are in adjacent buildings.
Is there an answer to this question: How many floors are in the chapel?

Answer: unanswerable


Question: Many sports popular today were formalised by British Public schools and universities in the 19th century. These schools produced the civil servants and military and naval officers required to build and maintain the British empire, and team sports were considered a vital tool for training their students to think and act as part of a team. Former public schoolboys continued to pursue these activities, and founded organisations such as the Football Association (FA). Today's association of football with the working classes began in 1885 when the FA changed its rules to allow professional players.
Is there an answer to this question: What changed in 1885 due to the FA changing rules?

Answer:
association of football with the working classes