Problem: The Bronx:

The consolidation of the Bronx into New York City proceeded in two stages. In 1873, the state legislature annexed Kingsbridge, West Farms and Morrisania to New York, effective in 1874; the three towns were abolished in the process. In 1895, three years before New York's consolidation with Brooklyn, Queens and Staten Island, the whole of the territory east of the Bronx River, including the Town of Westchester (which had voted in 1894 against consolidation) and portions of Eastchester and Pelham, were annexed to the city. City Island, a nautical community, voted to join the city in 1896.

When did New York City annex part of Pelham?
---
A: 1895

Problem: Alphanumeric LEDs are available in seven-segment, starburst and dot-matrix format. Seven-segment displays handle all numbers and a limited set of letters. Starburst displays can display all letters. Dot-matrix displays typically use 5x7 pixels per character. Seven-segment LED displays were in widespread use in the 1970s and 1980s, but rising use of liquid crystal displays, with their lower power needs and greater display flexibility, has reduced the popularity of numeric and alphanumeric LED displays.
What is another format that non-Alphanumeric LEDs are available in?
---
Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
It had been found that the proportion of non-repetitive DNA can vary a lot between species. Some E. coli as prokaryotes only have non-repetitive DNA, lower eukaryotes such as C. elegans and fruit fly, still possess more non-repetitive DNA than repetitive DNA. Higher eukaryotes tend to have more repetitive DNA than non-repetitive ones. In some plants and amphibians, the proportion of non-repetitive DNA is no more than 20%, becoming a minority component.
What is the percentage of non-repetitive DNA in E. coli?
A: unanswerable

Context and question: On 1 July 1967, BBC Two became the first television channel in Europe to broadcast regularly in colour, using the West German PAL system that is still in use today although being gradually superseded by digital systems. (BBC One and ITV began 625-line colour broadcasts simultaneously on 15 November 1969). Unlike other terrestrial channels, BBC Two does not have soap opera or standard news programming, but a range of programmes intended to be eclectic and diverse (although if a programme has high audience ratings it is often eventually repositioned to BBC One). The different remit of BBC2 allowed its first controller, Sir David Attenborough to commission the first heavyweight documentaries and documentary series such as Civilisation, The Ascent of Man and Horizon.
What happened on 1 July 1969?
Answer: unanswerable

Question: The three brothersRurik, Sineus, and Truvorestablished themselves in Novgorod, Beloozero, and Izborsk, respectively. Two of the brothers died, and Rurik became the sole ruler of the territory and progenitor of the Rurik Dynasty. A short time later, two of Rurik's men, Askold and Dir, asked him for permission to go to Tsargrad (Constantinople). On their way south, they discovered "a small city on a hill," Kiev, captured it and the surrounding country from the Khazars, populated the region with more Varangians, and "established their dominion over the country of the Polyanians."
Is there an answer to this question: What was the name of the small city on the hill that was discovered by Rurik's men?

Answer: Kiev

Problem: Film speed:

Film speed is used in the exposure equations to find the appropriate exposure parameters. Four variables are available to the photographer to obtain the desired effect: lighting, film speed, f-number (aperture size), and shutter speed (exposure time). The equation may be expressed as ratios, or, by taking the logarithm (base 2) of both sides, by addition, using the APEX system, in which every increment of 1 is a doubling of exposure; this increment is commonly known as a "stop". The effective f-number is proportional to the ratio between the lens focal length and aperture diameter, the diameter itself being proportional to the square root of the aperture area. Thus, a lens set to f/1.4 allows twice as much light to strike the focal plane as a lens set to f/2. Therefore, each f-number factor of the square root of two (approximately 1.4) is also a stop, so lenses are typically marked in that progression: f/1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, etc.

What is the effective f-number proportional to?
---
A:
the ratio between the lens focal length and aperture diameter