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A volcanic eruption in Iceland has sent ash across northern Europe. Airlines have stopped or changed the flights across the Atlantic Ocean, leaving hundreds of passengers stuck in airports.

Grirmsvom is one of the largest and most active volcanoes in Europe. What makes Grimsvom different is that it lies under a huge glacier（冰川） of ice up to 12 maters thick. The hot volcano heats up the ice above it, which then forms a layer（层）of water between the glacier and the volcano This layer of water puts pressure on the volcano, keeping it stable, As the water flows out from under the glacier, the pressure lifts. The lava（岩浆） from the volcano then comes up to the surface. This is exactly what happened today.

Now, airlines have to make changes to their flights so as not to fly through the clouds of volcanic ash. According to KLM. one of Europe’s biggest airlines, airplanes cannot go under the cloud or over it. Going through the cloud can result in ash getting stuck in the airplane’s engines, causing damage to the plane.

The eruption has also caused problems for animals in Iceland. The volcano left ash and sharp. Glass-like rocks all over the countryside. Farmers are keeping their animals inside to stop them from eating ash- covered grass to the sharp object.

What keeps Grimsvom still?

A. The slow flow of water B. The low water temperature

C. The thick glacier D. The water pressure

Which of the following is true?

A. People stop traveling in Europe

B. Airlines suffer from the loss of planes

C. It becomes dangerous for animals to eat outside

D. Farmers have lost many of their animals

This text is most probably taken from_______________.

A. a research paper B. a newspaper report

C. a class presentation D. a geography textbook.

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A dam is a man-made structure built across a river. Most dams are built to control a river’s water flow, improve navigation and control flooding. However, some dams are built to produce hydro-electric power.

Hydro-electric power is produced as water passes through a dam, and into a river below. The more water that passes through a dam, the more energy is produced. Once a dam is built, a man-made lake is created behind the dam.

Electricity is produced by a kind of equipment called a turbine(水轮机). Turbines contain metal coils(线圈) surrounded by magnets(磁铁). When the magnets move round rapidly over the metal coils, electricity is produced. Turbines are located inside dams. The falling water makes the magnets go around the coils.

Dams provide clean energy, but they can also harm the environment. Species that use rivers to reproduce are often hurt by dams. In the Northwest of the US, the population of fishes has dropped from 16 million to 2.5 million since hydro-electric plants were built on the Columbia River. Dams all over the world have hurt some species.

The highest dam in the Unites States is located near Oroville, California. The Oroville Dam towers 230 meters and is more than a mile wide. This dam was built in 1968, 22 years after the Hoover Dam. The Hoover Dam, on the Nevada-Arizona border controls the Colorado river. It is 221 meters high and has 2.6 million hectare-meters of water.

The highest dam in the world is the Nurek Dam on the Vakhsh River in Tadzikistan, a country in central Asia. This dam is 300 meters tall.

Which of the following statements is NOT true according to the passage?

A. Some dams are built for controlling a river’s water flow.

B. Hydro-electric power is usually produced through a dam.

C. Dams can offer energy and they are harmless to the environment.

D. Generally speaking, where there is a dam, there is a man-made lake.

The third paragraph mainly tells us _____.

A. how hydro-electric power is produced

B. What a turbine is and how it works

C. how the magnets and the metal coils work

D. how the falling water passes through a turbine

The dam which controls the Colorado river is ____.

A. the Oroville Dam B. the Hoover Dam C. the Nurek Dam D. the Vakhsh Dam