When we accept the evidence of our unaided eyes and describe the Sun as a yellow star, we have summed up the most important sing

admin2014-08-25  41

问题     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 (微不足道的) 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 and shorter light waves.
    That yellow "hump" will shift as the Sun evolves. and the light of the day will change accordingly. (80) It is natural to assume that as the Sun grows older, and uses up its hydrogen fuel—which it is now doing at the spanking rate of half a billion tons a second—it will become steadily colder and redder.
According to the passage, as the Sun continues to age, what color is it likely to become?

选项 A、Yellow.
B、Violet.
C、Red.
D、White.

答案C

解析 本题属细节判断题。可直接在最后一句找到答案,其句意是“很自然会想到,随着太阳的老化及氢燃料的日益耗用(目前它上面的氢燃料正在以每秒5亿吨的惊人速度燃烧着),太阳将会不断地变冷、变红。”
转载请注明原文地址:https://kaotiyun.com/show/fkxO777K
0

最新回复(0)