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    The light of the nearest star you see tonight has been for years. A. on the earth B. on the moon C. away from the sun D. away from the star 答案 DBD Passage 68 (福建省三校2010届高三上学期期中联考) B Many of the most damaging types of weather begin quickly, strike suddenly, and disappear rapidly, destroying small areas while leaving neighboring areas untouched．Such event as a tornadostruck the northeastern part of Edmonton, Alberta, in July 1987．Total damages from the tornado went beyond $250 million, the highest ever for any Canadian storm. Traditional computer models of the atmosphere have limited value in predicting short-lived local storms like the Edmonton tornado, because the available weather data are generally not detailed enough to allow computers to study carefully the slight atmospheric changes that come before these storms. In most nations, for example, weather-balloon observations are taken just once every twelve hours at places separated by hundreds of miles. With such limited data, traditional forecasting models do a much better job predicting general weather conditions over large areas than they do forecasting specific local events. Until recently, the observation intensive method needed for exact, very short-range forecasts, or “Nowcasts, was not possible. The cost of equipping and operating many thousands of conventional weather stations was extremely high, and the difficulties concerned in rapidly collecting and processing the weather data from such a network were hard to overcome. Fortunately, scientific and technological advances have overcome most of these problems. Radar systems and satellites are all able to make detailed, nearly continuous observation over large areas at a lower cost. Communications satellites can send out data around the world cheaply and immediately, and modern computers can quickly collect and analyze this large amount of weather information. Meteorologistsand computer scientists now work together to design computer programs and video equipment able to change weather data into words and graphic displaysthat forecasters can understand easily and quickly. As meteorologists have begun using these new technologies in weather forecasting offices, nowcasting is becoming a reality. 【查看更多】

     

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    阅读理解

    　　Light travels at a speed which is about a million times faster than that of sound. In one second, light travels about 300,000 kilometers, but sound travels only 344 metros. You can get some idea of this difference by watching the start of a running match. If you stand quite away from the starter（发令员）, you can see smoke come from his gun before the sound reaches your ears.

    　　The fast speed of light produces some strange facts. Sunlight takes about 8 minutes to reach us. If you look at the light of the moon tonight, remember that the light rays（射线）left the moon 1.3 seconds before they reached you. The nearest star is so far away that the light which you can see from it tonight to travel to you 4 years ago at a speed of nearly 2 million kilometers every minute. The light from some of tonight’s stars started on its journey towards you even before you were born.

    　　Thus, if we want to be honest, we cannot say, “The stars are shining brightly tonight.” We have to say, “The stars look pretty. They were shining four years ago but their light has just reached out earth.”

    1. The best title（题目）of this passage is ________.

    [　　]

    A. Light Travels Faster than Sound

    B. Stars Are Very Far Away from us

    C. The Speed of Light

    D. It’s Not Correct to Say “The Stars Are Shining Brightly Tonight”

    2. If you stand 200 metros away from a man who is firing a gun to start a running match, you will find out that ________.

    [　　]

    A. light travels a million times faster than sound

    B. the smoke of the gun gets into your sight after the sound of the gun-shot

    C. sound travels less fast than light

    D. the sound of the gun will reach you at the same time with the light of the smoke

    3. Sunlight obviously ________ than the light of the moon.

    [　　]

    A. has to travel a greater distance

    B. moves less quickly

    C. travels much more quickly

    D. is less powerful

    4. The scientific way of saying “The stars are shining brightly tonight” should be ________.

    [　　]

    A. the stars have been shining all the time

    B. the stars seen tonight will be shining four years later

    C. the stars were shining long ago but are seen tonight

    D. the star light seen tonight could be seen four years ago

    5. The light of the nearest star you see tonight has been ________ for years.

    [　　]

    A. on the earth　　　　    B. on the moon

    C. away from the sun　　   D. away from itself

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    阅读理解

    　　It is ten o'clock at night and you are outside. You can see many stars in the sky. Each star is another sun. The sky is big, and it hag many suns.

    　　Our sun is near to us. It warms us and gives us light in daytime. The stars are not near. We can see their light only at night, and they do not warm us.

    　　The stars are not all the same. Many stars are quite like our sun. They are the same size, and they have the same colour, yellow. Other stars are bigger or smaller. A “giant(巨人)” star is very, very big. A “dwarf(侏儒)”is a small star—smaller than the sun.

    　　Stars have different colours, too. They can be blue, orange, yellow, white or red. There are giants and dwarfs in all these colours. All stars are, of course, very hot. The hottest stars are the blue ones. White stars come next, they are less hot. Then yellow and orange stars are less hot again. Red stars are the least hot, and they are also the oldest stars.

    　　Light moves very quickly across the sky, eighteen million (18,000,000)kilometers in a minute. Our nearest star is a red dwarf. Its name is Proxima Centauri ( proxima ＝ nearest), and it gives a weak, red light. We can just see this light. It left Proxima Centauri 4.25 years ago, and now tonight, it is reaching cur eyes. Think about it! In one minute, 18,000,000 kilometres. So, in 4.25 years—well, how many kilometers? You can find the answer yourself.

    　　I will just say this: Proxima Centauri is a long way from us.

    1．According to the temperatures on stars, the right order from the lowest temperature to the highest is ________.

    [　　]

    A．red→yellow→white→blue

    B．orange→red→blue→white

    C．blue→white→yellow→red

    D．white→blue→orange→red

    2．All the following am right except ________.

    [　　]

    A．a “dwarf” is smaller than the sun

    B．there are dwarfs in different colours

    C．a “dwarf” is a small star

    D．dwarfs are the least hot

    3．How far away is the star Proxima Centauri from us?

    [　　]

    A．40,208,400,000,000 kilometres.

    B．9,460,800,000,000 kilometres.

    C．679,140,000,000 kilometres .

    D．279,225,000,000 kilometres .

    4．When we say “The star Procyon is ‘ten light years’ away.”, we mean ________.

    [　　]

    A．we can reach the star in ten years

    B．we first saw the star ten years ago

    C．the light left Procyon ten years ago

    D．Procyon has been that far away for ten years

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