Problem: There are many styles of mandolin, but four are common, the Neapolitan or round-backed mandolin, the carved-top mandolin and the flat-backed mandolin. The round-back has a deep bottom, constructed of strips of wood, glued together into a bowl. The carved-top or arch-top mandolin has a much shallower, arched back, and an arched topboth carved out of wood. The flat-backed mandolin uses thin sheets of wood for the body, braced on the inside for strength in a similar manner to a guitar. Each style of instrument has its own sound quality and is associated with particular forms of music. Neapolitan mandolins feature prominently in European classical music and traditional music. Carved-top instruments are common in American folk music and bluegrass music. Flat-backed instruments are commonly used in Irish, British and Brazilian folk music. Some modern Brazilian instruments feature an extra fifth course tuned a fifth lower than the standard fourth course.
Which style of mandolin has a shallower, arched back, and arched top?
The answer is the following: round-back

Problem: While the use of iron started to become more widespread around 1200 BC, mainly because of interruptions in the trade routes for tin, the metal is much softer than bronze. However, very small amounts of steel, (an alloy of iron and around 1% carbon), was always a byproduct of the bloomery process. The ability to modify the hardness of steel by heat treatment had been known since 1100 BC, and the rare material was valued for the manufacture of tools and weapons. Because the ancients could not produce temperatures high enough to melt iron fully, the production of steel in decent quantities did not occur until the introduction of blister steel during the Middle Ages. This method introduced carbon by heating wrought iron in charcoal for long periods of time, but the penetration of carbon was not very deep, so the alloy was not homogeneous. In 1740, Benjamin Huntsman began melting blister steel in a crucible to even out the carbon content, creating the first process for the mass production of tool steel. Huntsman's process was used for manufacturing tool steel until the early 1900s.
When did iron start to become melted by people?
The answer is the following: Middle Ages

Problem: In the 19th century, the monasteries built in the high Alps during the medieval period to shelter travelers and as places of pilgrimage, became tourist destinations. The Benedictines had built monasteries in Lucerne, Switzerland, and Oberammergau; the Cistercians in the Tyrol and at Lake Constance; and the Augustinians had abbeys in the Savoy and one in the center of Interlaken, Switzerland. The Great St Bernard Hospice, built in the 9th or 10th centuries, at the summit of the Great Saint Bernard Pass was shelter for travelers and place for pilgrims since its inception; by the 19th century it became a tourist attraction with notable visitors such as author Charles Dickens and mountaineer Edward Whymper.
What became tourist destinations during the 19th century?
The answer is the following: the monasteries built in the high Alps

Problem: Some of the earliest recorded observations ever made through a telescope, Galileo's drawings on 28 December 1612 and 27 January 1613, contain plotted points that match up with what is now known to be the position of Neptune. On both occasions, Galileo seems to have mistaken Neptune for a fixed star when it appeared closein conjunctionto Jupiter in the night sky; hence, he is not credited with Neptune's discovery. At his first observation in December 1612, Neptune was almost stationary in the sky because it had just turned retrograde that day. This apparent backward motion is created when Earth's orbit takes it past an outer planet. Because Neptune was only beginning its yearly retrograde cycle, the motion of the planet was far too slight to be detected with Galileo's small telescope. In July 2009, University of Melbourne physicist David Jamieson announced new evidence suggesting that Galileo was at least aware that the 'star' he had observed had moved relative to the fixed stars.
What happens when Neptune goes retrograde?
The answer is the following:
Earth's orbit takes it past an outer planet