The temperature of the sun is over 5,000 degrees Fahrenheit at the surface, but it rises to perhaps more than 16 million degrees

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问题     The temperature of the sun is over 5,000 degrees Fahrenheit at the surface, but it rises to perhaps more than 16 million degrees at the center. The sun is so much hotter than the Earth that matter can exist only as a gas, except at the core. In the core of the sun, the pressures are so great against the gases that, despite the high temperature, there may be a small solid core. However, no one really knows, since the center of the Sun can never be directly observed.
    Solar astronomers do know that the Sun is divided into five layers or zones. Starting at the outside and going down into the Sun, the zones are the corona, chromosphere, photosphere, convection and the sun has no solid surface, so it is hard to tell where the atmosphere ends and the main body of the Sun begins.
    The sun’s outermost layer begins about 10,000 miles above the visible surface and goes outward for millions of miles. This is the only part of the sun that can be seen during an e-clipse such as the one in February 1979. At any other time, the corona can be seen only when special instruments are used on cameras and other time, the corona can be seen only when special instruments are used on cameras and telescopes to shot out glare of the sun’s rays.
    The corona is a brilliant, pearly white, filmy light, about as bright as the full Moon. Its beautiful rays are a sensational sight during an eclipse. The corona’s rays flash out in a bril-liant fan that has wispy(纤细的) spike like rays near the sun’s north and south poles. The corona is thickest at the sun’s equator.
    The corona rays are made up of gases streaming outward at tremendous speeds and reaching a temperature of more than 2 million degrees Fahrenheit. The rays of gas thin out as they reach the space around the planets. By the time the sun’s corona rays reach the Earth, they are weak and invisible.
The purpose of the special instruments mentioned in the third paragraph is to

选项 A、magnify the image of the Sun
B、block out the Sun’s intense light
C、measure the amount of energy emitted by the Sun
D、photograph the Sun

答案B

解析 这也是一道细节题,就文章第三段最后一句话进行提问。这句话提到的观察日冕时,要在摄像机和望远镜上安装特殊设备,其目的就是要防止太阳强光的刺激。阅读时只要注意到这句话,答对该题不应有什么问题。
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