Although an alloy is technically an impure metal, when referring to alloys, the term "impurities" usually denotes those elements which are not desired. These impurities are often found in the base metals or the solutes, but they may also be introduced during the alloying process. For instance, sulfur is a common impurity in steel. Sulfur combines readily with iron to form iron sulfide, which is very brittle, creating weak spots in the steel. Lithium, sodium and calcium are common impurities in aluminium alloys, which can have adverse effects on the structural integrity of castings. Conversely, otherwise pure-metals that simply contain unwanted impurities are often called "impure metals" and are not usually referred to as alloys. Oxygen, present in the air, readily combines with most metals to form metal oxides; especially at higher temperatures encountered during alloying. Great care is often taken during the alloying process to remove excess impurities, using fluxes, chemical additives, or other methods of extractive metallurgy.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What element from the air does not easily combined with most metals?
Ah, so.. unanswerable

These styles generally have either two f-shaped soundholes like a violin (F-5 and A-5), or an oval sound hole (F-4 and A-4 and lower models) directly under the strings. Much variation exists between makers working from these archetypes, and other variants have become increasingly common. Generally, in the United States, Gibson F-hole F-5 mandolins and mandolins influenced by that design are strongly associated with bluegrass, while the A-style is associated other types of music, although it too is most often used for and associated with bluegrass. The F-5's more complicated woodwork also translates into a more expensive instrument.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What mandolin is not associated with Bluegrass music?
Ah, so.. unanswerable

In eukaryotes such as plants, protozoa and animals, however, "genome" carries the typical connotation of only information on chromosomal DNA. So although these organisms contain chloroplasts or mitochondria that have their own DNA, the genetic information contained by DNA within these organelles is not considered part of the genome. In fact, mitochondria are sometimes said to have their own genome often referred to as the "mitochondrial genome". The DNA found within the chloroplast may be referred to as the "plastome".
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What is not considered as part of the plastome?
Ah, so..
unanswerable