文档介绍：2014年职称英语考试卫生类C级补全短文练习(7)
Right now,an eruption is brewing in Yellowstone National during the next two hours,the park’s most famous geyser,Old Faithful,will begin gurgling boiling water and steam. 1
Old Faithful is not only a spectacular sight;it’s constant reminder that Yellowstone sits on one of the largest volcanoes in the you’ve never heard of Yellowstone’s volcano,you’re not alone. 2 Yet it has erupted three times during the last 2 million one of those eruptions spewed enough volcanic ash and other debris to blanket half the United States.
Yellowstone’s volcano is sometimes called a “supervolcano,” or extremely large and explosive caldera volcano. 3 .This supervolcano formed over a hot extremely hot area in Earth’s Valley,a volcano professor,said that as the crust moves across a hot spot,the hot spot melts a section of the plate moving over “one volcano after another.”
The Yellowstone hot spot melts thick continental crust,which may cause catastrophic
to experts the eruptions that created each of the three calderas in and around Yellowstone National Park were larger than any other volcanic eruption in recorded most recent eruption,which happened 640,000 years ago,produced at least cubic kilometers of ash and debris,which blanketed most of the western half of