Question: One of the most spectacular examples of obligate mutualism is between the siboglinid tube worms and symbiotic bacteria that live at hydrothermal vents and cold seeps. The worm has no digestive tract and is wholly reliant on its internal symbionts for nutrition. The bacteria oxidize either hydrogen sulfide or methane, which the host supplies to them. These worms were discovered in the late 1980s at the hydrothermal vents near the Galapagos Islands and have since been found at deep-sea hydrothermal vents and cold seeps in all of the world's oceans.
Try to answer this question if possible: When were the Galapagos Islands discovered?
Answer: unanswerable
Question: Bath Rugby play at the Recreation Ground in Bath, and the Somerset County Cricket Club are based at the County Ground in Taunton. The county gained its first Football League club in 2003, when Yeovil Town won promotion to Division Three as Football Conference champions. They had achieved numerous FA Cup victories over football League sides in the past 50 years, and since joining the elite they have won promotion again—as League Two champions in 2005. They came close to yet another promotion in 2007, when they reached the League One playoff final, but lost to Blackpool at the newly reopened Wembley Stadium. Yeovil achieved promotion to the Championship in 2013 after beating Brentford in the playoff final. Horse racing courses are at Taunton and Wincanton.
Try to answer this question if possible: Who did Yeovil Town beat in the 2005 championship game?
Answer: unanswerable
Question: In 1979, the Japanese state broadcaster NHK first developed consumer high-definition television with a 5:3 display aspect ratio. The system, known as Hi-Vision or MUSE after its Multiple sub-Nyquist sampling encoding for encoding the signal, required about twice the bandwidth of the existing NTSC system but provided about four times the resolution (1080i/1125 lines). Satellite test broadcasts started in 1989, with regular testing starting in 1991 and regular broadcasting of BS-9ch commencing on November 25, 1994, which featured commercial and NHK programming.
Try to answer this question if possible:  When did satellite test broadcasts of lo-Vision start?
Answer: unanswerable
Question: Melbourne (/ˈmɛlbərn/, AU i/ˈmɛlbən/) is the capital and most populous city in the Australian state of Victoria, and the second most populous city in Australia and Oceania. The name "Melbourne" refers to the area of urban agglomeration (as well as a census statistical division) spanning 9,900 km2 (3,800 sq mi) which comprises the broader metropolitan area, as well as being the common name for its city centre. The metropolis is located on the large natural bay of Port Phillip and expands into the hinterlands towards the Dandenong and Macedon mountain ranges, Mornington Peninsula and Yarra Valley. Melbourne consists of 31 municipalities. It has a population of 4,347,955 as of 2013, and its inhabitants are called Melburnians.
Try to answer this question if possible: What was Melbourne's population in 2013?
Answer:
4,347,955