Question: Read this and answer the question

Of his eight encyclicals, Pope Paul VI is best known for his encyclical Humanae vitae (Of Human Life, subtitled On the Regulation of Birth), published on 25 July 1968. In this encyclical he reaffirmed the Catholic Church's traditional view of marriage and marital relations and a continued condemnation of artificial birth control. There were two Papal committees and numerous independent experts looking into the latest advancement of science and medicine on the question of artificial birth control. which were noted by the Pope in his encyclical The expressed views of Paul VI reflected the teachings of his predecessors, especially Pius XI, Pius XII and John XXIII and never changed, as he repeatedly stated them in the first few years of his Pontificate

Which one of Paul Vi's encyclicals best known in Catholic history?
Answer: Humanae vitae
Question: Read this and answer the question

The international repertoire of music for mandolin is almost unlimited, and musicians use it to play various types of music. This is especially true of violin music, since the mandolin has the same tuning of the violin. Following its invention and early development in Italy the mandolin spread throughout the European continent. The instrument was primarily used in a classical tradition with Mandolin orchestras, so called Estudiantinas or in Germany Zupforchestern appearing in many cities. Following this continental popularity of the mandolin family local traditions appeared outside of Europe in the Americas and in Japan. Travelling mandolin virtuosi like Giuseppe Pettine, Raffaele Calace and Silvio Ranieri contributed to the mandolin becoming a "fad" instrument in the early 20th century. This "mandolin craze" was fading by the 1930s, but just as this practice was falling into disuse, the mandolin found a new niche in American country, old-time music, bluegrass and folk music. More recently, the Baroque and Classical mandolin repertory and styles have benefited from the raised awareness of and interest in Early music, with media attention to classical players such as Israeli Avi Avital, Italian Carlo Aonzo and American Joseph Brent.

When was the mandolin considered a fad?
Answer: early 20th century
Question: Read this and answer the question

William Champion's brother, John, patented a process in 1758 for calcining zinc sulfide into an oxide usable in the retort process. Prior to this, only calamine could be used to produce zinc. In 1798, Johann Christian Ruberg improved on the smelting process by building the first horizontal retort smelter. Jean-Jacques Daniel Dony built a different kind of horizontal zinc smelter in Belgium, which processed even more zinc. Italian doctor Luigi Galvani discovered in 1780 that connecting the spinal cord of a freshly dissected frog to an iron rail attached by a brass hook caused the frog's leg to twitch. He incorrectly thought he had discovered an ability of nerves and muscles to create electricity and called the effect "animal electricity". The galvanic cell and the process of galvanization were both named for Luigi Galvani and these discoveries paved the way for electrical batteries, galvanization and cathodic protection.

Who built the first horizontal retort smelter?
Answer:
Johann Christian Ruberg