雅思阅读模拟真题之eruption of mount st helens.docxVIP

智课网IELTS备考资料 雅思阅读模拟真题之Eruption of Mount St Helens 您当前的位置 ? 智课教育官网 ? 雅思 ? 预测真题 ? 文章正文  出国英语考试有哪些 雅思6.5是什么水平 雅思阅读评分标准 托福阅读评分标准 雅思和托福的区别  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: around 1900 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 and 1857. 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 remaine