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Hydrogen was liquefied for the first time by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask. He produced solid hydrogen the next year. Deuterium was discovered in December 1931 by Harold Urey, and tritium was prepared in 1934 by Ernest Rutherford, Mark Oliphant, and Paul Harteck. Heavy water, which consists of deuterium in the place of regular hydrogen, was discovered by Urey's group in 1932. François Isaac de Rivaz built the first de Rivaz engine, an internal combustion engine powered by a mixture of hydrogen and oxygen in 1806. Edward Daniel Clarke invented the hydrogen gas blowpipe in 1819. The Döbereiner's lamp and limelight were invented in 1823.
Who was the first to liquidize hydrogen?
A: James Dewar

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Archaeological evidence shows that Homo erectus lived in the region now known as Myanmar as early as 400,000 years ago. The first evidence of Homo sapiens is dated to about 11,000 BC, in a Stone Age culture called the Anyathian with discoveries of stone tools in central Myanmar. Evidence of neolithic age domestication of plants and animals and the use of polished stone tools dating to sometime between 10,000 and 6,000 BC has been discovered in the form of cave paintings near the city of Taunggyi.
What extinct species of hominid that lived throughout most of the Pleistocene geological period is believed to have dwelled in Myanmar?
A: Homo erectus

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Since the formal adoption of digital video broadcasting's (DVB) widescreen HDTV transmission modes in the early 2000s; the 525-line NTSC (and PAL-M) systems, as well as the European 625-line PAL and SECAM systems, are now regarded as standard definition television systems.
When was widescreen HDTV transmission modes formally adopted?
A: early 2000s

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Occasional severe flooding is experienced. There was the Great Mississippi Flood of 1927, the Great Flood of 1993, and widespread flooding and mudslides caused by the 1982-1983 El Niño event in the western United States. Localized flooding can, however, occur anywhere, and mudslides from heavy rain can cause problems in any mountainous area, particularly the Southwest. Large stretches of desert shrub in the west can fuel the spread of wildfires. The narrow canyons of many mountain areas in the west and severe thunderstorm activity during the summer lead to sometimes devastating flash floods as well, while Nor'Easter snowstorms can bring activity to a halt throughout the Northeast (although heavy snowstorms can occur almost anywhere).
What is the name of the major event that caused flooding in the eastern United States?
A:
unanswerable