[单项选择]

When we accept the evidence of our unaided eyes and describe the Sun as a yellow star, we have summed up the most important single fact about it--at this moment in time. It appears probable, however, that sunlight will be the color we know for only a negligibly (微不足道) small part of the Sun’s history.
Stars, like individuals, age and change. As we look out into space, we see around us stars at all stages of evolution.There are faint blooded dwarfs so cool that their surface temperature is a mere 4,000 degrees Fahrenheit; there are scaring ghosts blazing at 100,000 degrees Fahrenheit and almost too hot to be seen, for the great part of their radiation is in the invisible ultraviolet range. Obviously, the "daylight" produced by any star depends on its temperature; today (and for ages to come) our Sun is at about 10,000 degrees Fahrenheit, and this means that most of the Sun’s light is concentrated in the yellow band of the spectrum, falling slowly in in
A. They are short-lived.
B. They are mysterious.
C. They are frightening.
D. They are nearly invisible.

[单项选择]When we accept the evidence of our unaided eyes and describe the Sun as a yellow star, we have summed up the most important single fact about it--at this moment in time. It appears probable, however, that sunlight will be the color we know for only a negligibly (微不足道) small part of the Sun’s history.
Stars, like individuals, age and change. As we look out into space, we see around us stars at all stages of evolution.There are faint blooded dwarfs so cool that their surface temperature is a mere 4,000 degrees Fahrenheit; there are scaring ghosts blazing at 100,000 degrees Fahrenheit and almost too hot to be seen, for the great part of their radiation is in the invisible ultraviolet range. Obviously, the "daylight" produced by any star depends on its temperature; today (and for ages to come) our Sun is at about 10,000 degrees Fahrenheit, and this means that most of the Sun’s light is concentrated in the yellow band of the spectrum, falling slowly in intensity toward both the longer
A. Faint dwarf stars.
B. The evolution cycle of the Sun.
C. The Sun’s fuel problem.
D. The dangers of invisible radiation.

[单项选择]

[听力原文]
When we accept the evidence of our unaided eyes and describe the Sun as a yellow star, we have summed up the most important single fact about it—at this moment in time. It appears probable, however, that sunlight will be the color we know for only a small part of the Sun’s history.
Stars, like individuals, age and change. As we look out into space. We see around us stars at all stages of evolution. There are faint bloodred dwarfs school that their surface temperature is a mere 4,000 degrees Fahrenheit, there are searing ghosts blazing at 100,000 degrees Fahrenheit and almost too hot to be seen, for the great part of their radiation is in the invisible ultraviolet range. Obviously, the "daylight" produced by any star depends on its temperature; today (and for ages to come) our Sun is at about 10,000 degrees Fahrenheit, and this means that most of the Sun’s light is concentrated in the yellow band of the spectrum, falling slowly in
A. It is too cold.
B. It always remains the same.
C. It appears yellow.
D. It has a short history.

[单项选择]When we see well, we do not think about our eyes very often. (79) It is only when we cannot see perfectly that we realize how important our eyes are.
People who are nearsighted can only see things that are very close to their eyes. Everything else seems blurry(模糊的).Many people who do a lot of close work, such as writing, reading and sewing, become nearsighted. Then they have to wear glasses in order to see distant objects clearly.
People who are farsighted suffer from just the opposite problem. They can see things that are far away, but they have difficulty in reading a book unless they hold it at arm’s length. If they want to do much reading, they must get glasses, too.
Other people do not see clearly because their eyes are not exactly the right shape. They have what is called astigmatism (散光). This, too, can be corrected by glasses. Some people’s eyes become cloudy because of cataracts(白内障). Long ago these people often became blind. Now, however, it is possible
A. experience
B. react
C. feel pain
D. imagine