Input: Read this: Much of mandolin development revolved around the soundboard (the top). Pre-mandolin instruments were quiet instruments, strung with as many as six courses of gut strings, and were plucked with the fingers or with a quill. However, modern instruments are louder—using four courses of metal strings, which exert more pressure than the gut strings. The modern soundboard is designed to withstand the pressure of metal strings that would break earlier instruments. The soundboard comes in many shapes—but generally round or teardrop-shaped, sometimes with scrolls or other projections. There is usually one or more sound holes in the soundboard, either round, oval, or shaped like a calligraphic F (f-hole). A round or oval sound hole may be covered or bordered with decorative rosettes or purfling.
Question: What are the sound holes covered with? 

Output: bordered with decorative rosettes or purfling


QUES: Many sensor systems rely on light as the signal source. LEDs are often ideal as a light source due to the requirements of the sensors. LEDs are used as motion sensors, for example in optical computer mice. The Nintendo Wii's sensor bar uses infrared LEDs. Pulse oximeters use them for measuring oxygen saturation. Some flatbed scanners use arrays of RGB LEDs rather than the typical cold-cathode fluorescent lamp as the light source. Having independent control of three illuminated colors allows the scanner to calibrate itself for more accurate color balance, and there is no need for warm-up. Further, its sensors only need be monochromatic, since at any one time the page being scanned is only lit by one color of light. Since LEDs can also be used as photodiodes, they can be used for both photo emission and detection. This could be used, for example, in a touchscreen that registers reflected light from a finger or stylus. Many materials and biological systems are sensitive to, or dependent on, light. Grow lights use LEDs to increase photosynthesis in plants, and bacteria and viruses can be removed from water and other substances using UV LEDs for sterilization.

What video game console doesn't use infrared LEDs?
What is the answer?
ANS: unanswerable


QUES: In 1977, Elizabeth marked the Silver Jubilee of her accession. Parties and events took place throughout the Commonwealth, many coinciding with her associated national and Commonwealth tours. The celebrations re-affirmed the Queen's popularity, despite virtually coincident negative press coverage of Princess Margaret's separation from her husband. In 1978, the Queen endured a state visit to the United Kingdom by Romania's communist dictator, Nicolae Ceaușescu, and his wife, Elena, though privately she thought they had "blood on their hands". The following year brought two blows: one was the unmasking of Anthony Blunt, former Surveyor of the Queen's Pictures, as a communist spy; the other was the assassination of her relative and in-law Lord Mountbatten by the Provisional Irish Republican Army.
In what year did Nicolae Ceausescu die?

ANS: unanswerable


For administrative purposes, the Federal District is divided into 16 "delegaciones" or boroughs. While not fully equivalent to a municipality, the 16 boroughs have gained significant autonomy, and since 2000 their heads of government are elected directly by plurality (they were previously appointed by the head of government of the Federal District). Given that Mexico City is organized entirely as a Federal District, most of the city services are provided or organized by the Government of the Federal District and not by the boroughs themselves, while in the constituent states these services would be provided by the municipalities. The 16 boroughs of the Federal District with their 2010 populations are:
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Who provides the city services?
Ah, so.. Government of the Federal District


Question: All England matches are broadcast with full commentary on BBC Radio 5 Live. From the 2008–09 season until the 2017–18 season, England's home and away qualifiers, and friendlies both home and away are broadcast live on ITV (often with the exception of STV, the ITV affiliate in central and northern Scotland). England's away qualifiers for the 2010 World Cup were shown on Setanta Sports until that company's collapse. As a result of Setanta Sports's demise, England's World Cup qualifier in Ukraine on 10 October 2009 was shown in the United Kingdom on a pay-per-view basis via the internet only. This one-off event was the first time an England game had been screened in such a way. The number of subscribers, paying between £4.99 and £11.99 each, was estimated at between 250,000 and 300,000 and the total number of viewers at around 500,000.
Try to answer this question if possible: What was the first season in which England's qualifiers and friendlies were broadcast on ITV?
Answer: 2008–09


Context and question: New Delhi lies on several fault lines and thus experiences frequent earthquakes, most of them of mild intensity. There has, however, been a spike in the number of earthquakes in the last six years, most notable being a 5.4 magnitude earthquake in 2015 with its epicentre in Nepal, a 4.7-magnitude earthquake on 25 November 2007, a 4.2-magnitude earthquake on 7 September 2011, a 5.2-magnitude earthquake on 5 March 2012, and a swarm of twelve earthquakes, including four of magnitudes 2.5, 2.8, 3.1, and 3.3, on 12 November 2013.
How many earthquakes occurred on March 5, 2012?
Answer:
twelve