2. 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, chromospheres, photosphere, convection zone, and finally the core. The first three zones are regarded as the Sun’s atmosphere. But since the Sun has no solid surface, it is hard to tell where the atmosphere ends and the main body of the Sun begins.

3. 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 eclipse 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 telescopes to keep out the glare of the Sun’s rays.

4. 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 brilliant fan that has wispy spikelike rays near the Sun’s north and south poles. The corona is thickest at the Sun’s equator.

5. 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.

51. The temperature of the Sun at the center is__________.
A. over 5,000 degrees Fahrenheit
B. more than 5,000 degrees Centigrade
C. over 16,000,000 degrees Fahrenheit
D. more than 16,000,000 degrees Centigrade
52. One thing that is sure about the core of the Sun is that__________.
A. it is gas        B. it is solid
C. the temperature is low     D. the pressure is great
53. The zone that is NOT regarded as the Sun’s atmosphere is__________.
A. convection zone       B. corona zone
C. chromospheres zone      D. photosphere zone
54. Paragraph 2 is mainly about__________.
A. how the Sun evolved      B. the structure of the Sun
C. why scientists study the Sun    D. the main body of the Sun
55. The word “glare” in Paragraph 3 is closest in meaning to__________.
A. glitter         B. gleam
C. blaze         D. fire
56.The word “one” in Paragraph 3 refers to__________.
A. the Sun         B. the corona
C. an eclipse        D. the surface
57. The corona can be seen__________.
A. only in an eclipse
B. with naked eyes
C. with any cameras or telescopes
D. with cameras equipped with special instruments
58. Which is NOT true about the corona?
A. It is the outmost layer of the Sun.
B. It is very bright as the full Moon.
C. It is as white as pearl.
D. It is the thinnest at the Sun’s equator.
59. The word “sensational” in Paragraph 4 is closest in meaning to__________.