阅读理解 Sometimes in the month of November, a special event happens in the sky that

阅读理解

Sometimes in the month of November, a special event happens in the sky that observers may remember for a lifetime. The event is more than a meteor shower(流星雨) . It is a meteor storm .

Meteors are pieces of rock from space that burn up in our atmosphere(大气) . Meteor showers happen when the Earth passes through a large amount of space material during its orbit (按轨道运行) around the sun.

However, thousands of meteors fall during a meteor storm. Some of them may briefly shine brighter than any star in the sky.

The Leonid meteor shower happens every November. In most years, it is not unusual. Leonid meteors fall at an average rate of only fifteen each hour. But every thirty-three years art object passes through our solar system(太阳系) that changes the Leonid meteor shower.

A comet(彗星) is a large body of gas, ice and rock. Comets leave behind these materials as they orbit the sun. Each year around November 18th, the Earth passes through material left behind by a comet called Tempel-Tuttle .

In the February of 1998, comet Tempel-Tuttle returned to the inner solar system. Astronomers(天文学家) have found that the Leonid meteor shower can become very active for about five years after the appearance of that comet.

Astronomers also have discovered that each appearance of comet Tempel-Tuttle leaves behind a different path of material. This discovery has permitted astronomers to know when the Leonid meteor shower may be most intense. Some astronomers believe the Leonids this month may be a meteor storm .

In 1833, observers in the eastern United States saw an intense meteor storm. One person estimated that meteors fell at a rate of ten-thousand an hour above West Point, New York. In 1966, people in the western United States saw another intense Leonid meteor storm.

This year, astronomers believe that there will he two periods of heavy meteor activity starting on November 18th. At Ten Hours Universal Time, observers in North America should see a large number of meteors .

Another period of meteor activity should happen at about Eighteen Hours Universal Time. Observers in East Asia and western Australia will see it best. Astronomers who have researched the Leonids say the best chance to see a meteor storm may he this year and next year.

1．This passage mainly tells us about a kind of ________.

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A．stranger weather

B．strange material

C．atmospheric phenomenon(大气现象)

D．comet called Tempel-Tuttle

2．The writer thinks that when people see a meteor storm they will be ________.

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3．When a meteor storm happens, winch of the following will NOT happen?

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A．Rocks from space run into our atmosphere.

B．The Earth passes through a large amount of space material.

C．A comet orbits the Earth.

D．Meteors fall heavily.

4．How do astronomers know the Leonid this month may be a meteor storm?

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A．From the appearance of comets .

B．From the different types of Tempel-Tuttle when a comet appears.

C．Because the Tempel-Tuttle returned to the inner solar system.

D．Because every thirty-five years an object passes through materials left by the Tempel-Tuttle.

试题答案

答案：C;D;C;A