Problem: Through the 1960s, 1970s, and 1980s, various methods to improve the dynamic range of mass-produced records involved highly advanced disc cutting equipment. These techniques, marketed, to name two, as the CBS DisComputer and Teldec Direct Metal Mastering, were used to reduce inner-groove distortion. RCA Victor introduced another system to reduce dynamic range and achieve a groove with less surface noise under the commercial name of Dynagroove. Two main elements were combined: another disk material with less surface noise in the groove and dynamic compression for masking background noise. Sometimes this was called "diaphragming" the source material and not favoured by some music lovers for its unnatural side effects. Both elements were reflected in the brandname of Dynagroove, described elsewhere in more detail. It also used the earlier advanced method of forward-looking control on groove spacing with respect to volume of sound and position on the disk. Lower recorded volume used closer spacing; higher recorded volume used wider spacing, especially with lower frequencies. Also, the higher track density at lower volumes enabled disk recordings to end farther away from the disk center than usual, helping to reduce endtrack distortion even further.
What did closer groove spacing result in?
The answer is the following: Lower recorded volume

Problem: According to his autobiography, Avicenna had memorised the entire Quran by the age of 10. He learned Indian arithmetic from an Indian greengrocer,ءMahmoud Massahi and he began to learn more from a wandering scholar who gained a livelihood by curing the sick and teaching the young. He also studied Fiqh (Islamic jurisprudence) under the Sunni Hanafi scholar Ismail al-Zahid. Avicenna was taught some extent of philosophy books such as Introduction (Isagoge)'s Porphyry (philosopher), Euclid's Elements, Ptolemy's Almagest by an unpopular philosopher, Abu Abdullah Nateli, who claimed philosophizing.
What was one philosophy book that Avicenna was taught from?
The answer is the following: Euclid's Elements

Problem: The concept of biological race has declined significantly in frequency of use in physical anthropology in the United States during the 20th century. A majority of physical anthropologists in the United States have rejected the concept of biological races. Since 1932, an increasing number of college textbooks introducing physical anthropology have rejected race as a valid concept: from 1932 to 1976, only seven out of thirty-two rejected race; from 1975 to 1984, thirteen out of thirty-three rejected race; from 1985 to 1993, thirteen out of nineteen rejected race. According to one academic journal entry, where 78 percent of the articles in the 1931 Journal of Physical Anthropology employed these or nearly synonymous terms reflecting a bio-race paradigm, only 36 percent did so in 1965, and just 28 percent did in 1996.
What concept's use has declined significantly in the U.S. during the 20th century?
The answer is the following: biological race

Problem: The Order has six officials: the Prelate; the Dean; the Secretary; the Registrar; the King of Arms; and the Usher. The Bishop of London, a senior bishop in the Church of England, serves as the Order's Prelate. The Dean of St Paul's is ex officio the Dean of the Order. The Order's King of Arms is not a member of the College of Arms, as are many other heraldic officers. The Usher of the Order is known as the Gentleman Usher of the Purple Rod; he does not – unlike his Order of the Garter equivalent, the Gentleman Usher of the Black Rod – perform any duties related to the House of Lords.
Who serves as the Order's Prelate?
The answer is the following:
The Bishop of London, a senior bishop in the Church of England