Problem: For collectable or nostalgia purposes, or for the benefit of higher-quality audio playback provided by the 78 rpm speed with newer vinyl records and their lightweight stylus pickups, a small number of 78 rpm records have been released since the major labels ceased production. One of the first attempts at this was in the 1950s, when inventor Ewing Dunbar Nunn founded the label Audiophile Records, which released, in addition to standard 33 1/3 rpm LPs, 78 rpm-mastered albums that were microgroove and pressed on vinyl (as opposed to traditional 78s, with their shellac composition and wider 3-mil sized grooves). This was done by the label mainly to take advantage of the wider audio frequency response that faster speeds like 78 rpm can provide for vinyl microgroove records, hence the label's name (obviously catering to the audiophiles of the 1950s "hi-fi" era, when stereo gear could provide a much wider range of audio than before). Also in the late 1950s, Bell Records released a few budget-priced 7" microgrooved records at 78 rpm.
Who released 7" microgrooved records in the 1950s?
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Answer: Bell Records

Problem: Less than 1% of all species that have been described have been studied beyond simply noting their existence. The vast majority of Earth's species are microbial. Contemporary biodiversity physics is "firmly fixated on the visible [macroscopic] world". For example, microbial life is metabolically and environmentally more diverse than multicellular life (see e.g., extremophile). "On the tree of life, based on analyses of small-subunit ribosomal RNA, visible life consists of barely noticeable twigs. The inverse relationship of size and population recurs higher on the evolutionary ladder"to a first approximation, all multicellular species on Earth are insects". Insect extinction rates are highsupporting the Holocene extinction hypothesis.
What type of science is firmly fixated on RNA?
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Answer: unanswerable

Problem: There are 29 isotopes of copper. 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper; they both have a spin of 32. The other isotopes are radioactive, with the most stable being 67Cu with a half-life of 61.83 hours. Seven metastable isotopes have been characterized, with 68mCu the longest-lived with a half-life of 3.8 minutes. Isotopes with a mass number above 64 decay by , whereas those with a mass number below 64 decay by +. 64Cu, which has a half-life of 12.7 hours, decays both ways.
Which isotope makes up about 69% of natural copper?
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Answer:
63Cu