Krakatau Volcano (喀拉喀托火山) is on a small island in Indonesia. It had been peaceful for about 200 years before it erupted (爆发) in 1883.

The first signs of the activity of the volcano appeared in May 1883, when fire and smoke could be seen at the top of the mountain. Great noise could be heard even in Jakarta, a hundred miles away. Later the activity grew much greater. The peak (山顶) was covered with smoke and fire; the smoke at one time was seventeen miles high in the air. The lava—soft and hot rock—shot up into the air and rolled down the sides of the mountain.

The mouth of the volcano was not at the peak of the mountain but on its side, close to the sea. As it grew bigger and bigger with the eruption, the sea water got into it. When the sea water reached the lava inside the volcano, it made the upper part of the lava colder and harder. And this sealed off (封住) the rest of the lava below. As the inside of the lava could not break through the seal, the pressure (压力) built up until the mountain blew up.

The eruption of the volcano was followed by several earthquakes which brought about bad results. About 36,000 people were killed and many towns and villages near the sea were completely destroyed by the great waves which the earthquake caused.

1．Give the correct order of the course of volcano eruption.

①The peak was covered with smoke and fire.

②Fire and smoke could be seen at the top of the mountain.

③Great noise could be heard a hundred miles away.

④The lava shot into the air and rolled down the sides of the mountain.

A．①②③④ 　　　　 B．①③②④

C．②③①④ 　　　　 D．④①③②

2．What makes the volcano erupt?

A．The sea water which goes into the volcano.

B．The lava (岩浆)．

C．The pressure which is bigger and bigger.

D．All of the above.

3．Where is the mouth of the volcano?

A．At the peak of the mountain.

B．On the side of the mountain near the sea.

C．At the foot of the mountain.

D．Inside the mountain.

 

　　Krakatau Volcano(克拉克托火山)is in a small island in Indonesia.It had been peaceful for about 200 years before it erupted(爆发)in 1883.

　　The first signs of the activity of the volcano appeared in May 1883,when fire and smoke could be seen at the top of the mountain.Great noise could be heard even in Jakarta a hundred miles away.Later the activity grew much greater.The peak(山顶)was covered with smoke and fire;the smoke at one time was seventeen miles high in the air.The lava—soft and hot rock—shot up into the air and roiled down the sides of the mountain.

　　The mouth of the volcano was not at the peak of the mountain but on its side,close to the sea.As it grew bigger and bigger with the eruption,the sea water got into it.When the sea water reached the lava inside the volcano,it made the upper part of the lava colder and harder.And this sealed off(封住)the rest of the lava below.As the inside of the lava could not break through the seal,the pressure(压力)built up until the mountain blew up.

　　The eruption of the volcano was followed by several earthquakes which brought about bad result.About 36 000 people were killed and many towns and villages near the sea were completely destroyed by the great waves which the earthquake caused.

1.Give the correct order of the course of volcano eruption.

①The peak was covered with smoke and fire.

②Fire and smoke could be seen at the top of the mountain.

③Great noise could be heard a hundred miles away.

④The lava shot into the air and rolled down the sides of the mountain.

A.①②③④　　　　　　 B.①③②④　　　　　　 C.②③①④　　　　　　 D.④①③②

2.What makes volcanoes erupt？

A.The sea water which goes into the volcano.　　　　B.The lava(岩浆).

C.The pressure which is bigger and bigger.　　　　 D.All the above.

3.Where is the mouth of a volcano？

A.At the peak of the mountain.

B.On the side of the mountain near the sea.

C.At the foot of the mountain.

D.Inside the mountain.

Scientists have searched for many years for a method to tell whether a volcano（火山）explosion will be small or large. Now, four scientists say they have discovered something in lava（熔岩）that will help do this. They did the research on Mount Unzen on the southern Japanese island of Kyushu.

Mount Unzen exploded in November, 1990. Since then, more explosions have killed 43 people and destroyed the homes of more than 2,000 others. The volcano is still active today.

The scientists say the lava of the volcano contains high level of an element（成份），which is a sign of the presence of the lava from deep in the earth, not from the surface. They say it shows that the lava coming directly from inside the earth is connected with huge explosions instead of smaller ones.

The scientists examined the lava from 18 explosions of Mount Unzen that took place during many thousands of years. They also studied the lava from other volcanoes in the area that are older than Mount Unzen. The lava studied came from both large and small explosions. The scientists found that large explosions contained more of the element than small ones. The scientists say if they had known this two years earlier, they could have warned the people living in the area near Mount Unzen and saved many lives.

56. Scientists have searched for a long time in order to ______.

A. tell whether a volcano explosion will be small or large

B. tell whether a volcano explosion will be worthy or not

C. tell the number of active volcanoes in the world

D. find if there is any volcano in Japan

57. From the passage we learn that Mount Unzen is the name of ______.

A. an active volcano

B. a Japanese island

C. a huge volcano explosion

D. a kind of lava

58. Where does lava come from?

A. It comes from the deepest part of the ocean.

B. It comes from the earth surface.

C. Not mentioned in the passage.

D. It is from deep part in the earth.

59. The four scientists discovered that the level of the element contained in the lava could tell ______.

A. the place of a possible explosion

B. the degree of a volcano explosion

C. the number of volcano explosions

D. the time of a possible explosion

60. The research of the four scientists was based on ______.

A. the lava from different explosions in the area

B. the presence of the lava from the surface

C. the damages caused by the 1990 explosion

D. the lava that caused explosions