Problem: Many mechanical aids to calculation and measurement were constructed for astronomical and navigation use. The planisphere was a star chart invented by Abū Rayhān al-Bīrūnī in the early 11th century. The astrolabe was invented in the Hellenistic world in either the 1st or 2nd centuries BC and is often attributed to Hipparchus. A combination of the planisphere and dioptra, the astrolabe was effectively an analog computer capable of working out several different kinds of problems in spherical astronomy. An astrolabe incorporating a mechanical calendar computer and gear-wheels was invented by Abi Bakr of Isfahan, Persia in 1235. Abū Rayhān al-Bīrūnī invented the first mechanical geared lunisolar calendar astrolabe, an early fixed-wired knowledge processing machine with a gear train and gear-wheels, circa 1000 AD.
The first astrolabe with a mechanical calendar was invented where?
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Answer: Persia


Problem: A dense wave of smog began in the Central and Eastern part of China on 2 December 2013 across a distance of around 1,200 kilometres (750 mi), including Tianjin, Hebei, Shandong, Jiangsu, Anhui, Shanghai and Zhejiang. A lack of cold air flow, combined with slow-moving air masses carrying industrial emissions, collected airborne pollutants to form a thick layer of smog over the region. The heavy smog heavily polluted central and southern Jiangsu Province, especially in and around Nanjing, with its AQI pollution Index at "severely polluted" for five straight days and "heavily polluted" for nine. On 3 December 2013, levels of PM2.5 particulate matter average over 943 micrograms per cubic metre, falling to over 338 micrograms per cubic metre on 4 December 2013. Between 3:00 pm, 3 December and 2:00pm, 4 December local time, several expressways from Nanjing to other Jiangsu cities were closed, stranding dozens of passenger buses in Zhongyangmen bus station. From 5 to 6 December, Nanjing issued a red alert for air pollution and closed down all kindergarten through middle schools. Children's Hospital outpatient services increased by 33 percent; general incidence of bronchitis, pneumonia, upper respiratory tract infections significantly increased. The smog dissipated 12 December. Officials blamed the dense pollution on lack of wind, automobile exhaust emissions under low air pressure, and coal-powered district heating system in North China region. Prevailing winds blew low-hanging air masses of factory emissions (mostly SO2) towards China's east coast.
How long was Nanjing ranked as "severely polluted" during this wave?
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Answer: five straight days


Problem: Along with the rest of South West England, Plymouth has a temperate oceanic climate (Köppen Cfb) which is generally wetter and milder than the rest of England. This means a wide range of exotic plants can be grown. The annual mean temperature is approximately 11 °C (52 °F). Due to the modifying effect of the sea the seasonal range is less than in most other parts of the UK. As a result of this summer highs are lower than its southerly latitude should warrant, but as a contrast the coldest month of February has mean minimum temperatures as mild as between 3 and 4 °C (37 and 39 °F). Snow is rare, not usually equating to more than a few flakes, but there have been exclusions, namely the European winter storms of 2009-10 which, in early January, covered Plymouth in at least 1 inch (2.5 cm) of snow; more on higher ground. Another period of notable snow occurred from 17–19 December 2010 when up to 8 inches (20 cm) of snow fell through the period – though only 2 inches (5.1 cm) would lie at any one time due to melt. Over the 1961–1990 period, annual snowfall accumulation averaged less than 7 cm (3 in) per year. July and August are the warmest months with mean daily maxima over 19 °C (66 °F).
What month in Plymouth has the lowest temperatures?
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Answer:
February