摘要：-Oh dear ! I’ve just broken a window. - . It can’t be helped . A. Never mind B. All right C. That’s fine D. Not at all Part 6 Reading: Read and then ask and answer five questions on the passage, using who, what, where, when or how. Have you ever seen a Volcano? A volcano is one of the most surprising and frightening forces of nature. Perhaps you have seen pictures of these “fireworks’’ of nature in action. Any natural opening in the earth’s crust, called a fissure where melted rock ,ash, gases, and steam come out, is called a volcano. Volcanoes look like mountains, but they are really flat land that is pushed upward because of the pressure below the earth. There are thousands of volcanoes all over the world. Volcanoes are formed when the earth’s plates shift. There are five basic types of volcanoes: Caldera, Cone, Lava Dome, Shield, and Strato. Volcanoes are put into these five categories according to how they are formed, how they erupt, and where they are formed. When people think of volcanoes, they think of great explosions or eruptions, but they can also be little lava flows. Big explosions throw out new lava and other fragments such as hot volcanic rock and ash. Eruptions can destroy a whole island or town if they are very strong and violent. When lava flows from the volcano, it moves in large rivers across the land. It burns everything in its way. People who live near active volcanoes have to pay attention to the eruption warnings given by the scientists. It is important for scientists to know what is happening with a volcano. Volcanoes act in certain ways before erupting. Scientists look for ways to tell when a volcano is about to erupt by studying how the magma below the volcano is moving. If the magma is rising, three things begin to happen. First, earthquakes and other seismic activities begin. Second, the volcano begins to get larger at the top or back side. Third, volcanic gases are released from vents. These three events help scientists know when the volcano is about to erupt. If a volcano begins to act as it is going to erupt, scientists visit the volcano to study it for 24 hors a day. Many scientists work together to see how the volcano affects land, water, and animals before and after an eruption.

网址：http://m.1010jiajiao.com/timu3_id_3036367[举报]