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Reading Passage 1 You should spend about20 minutes on Questions 1-11 which are based on Reading Passage 1. The Spectacular Eruption of Mount: St. Helens A The eruption in May 1980 of Mount St. Helens, Washington State, astounded the world with its violence. A gigantic explosion tore much of the volcanos summit to fragments; the energy released was equal to that of 500 of the nuclear bombs that destroyed Hiroshima in 1945. B The event occurred along the boundary of two of the moving plates that make up the Earths crust. They meet at the junction of the North American continent and the Pacific Ocean. One edge of the continental North .American plate over-rides the oceanic Juan de Fuca micro-plate, producing the volcanic Cascade range that includes Mounts Baker, Rainier and Hood, and Lassen Peak as well as Mount St. Helens. C Until Mount St. Helens began to stir, only Mount Baker and Lassen Peak had shown signs of life during the 20th century. According to geological evidence found by the United States Geological Survey, there had been two major eruptions of Mount St. Helens in the recent (geologically speaking) past: around1900 B. C., and about A. D. 1500. Since the arrival of Europeans in the region, it had experienced a single period of spasmodic activity, between 1831 and1857. Then, for more than a century, Mount St. Helens lay dormant. D By 1979, the Geological Survey alerted by signs of renewed activity, had been monitoring the volcano for 18 months. It warned the local population against being deceived by the mountains outward calm, and forecast that an eruption would take place before the end of the century. The inhabitants of the area did not have to wait that long. On March 27,1980, a few clouds of smoke formed above the summit, and slight tremors were felt. On the 28th, larger and darker clouds consisting of gas and ashes, emerged and climbed as high as 20,000 feet. In April a slight lull ensued, but the volcanologists remained pessimistic. Then, in earl