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

admin2013-07-02  30

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 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 so cool 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 intensity toward both the longer and shorter light waves.
    That yellow "hump" will shift as the Sun evolves, and the light of day will change accordingly. 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, which of the following descriptions are not true? (  )

选项 A、Through our own unaided eyes, we will find that the yellow sunlight will change its color little by little.
B、The Sun, as a star, like an individual, always ages and changes.
C、Obviously, the "daylight" produced by any star doesn’t depend on its temperature.
D、Now, the Sun is using its hydrogen fuel at a very rapid speed.

答案C

解析 判断题。“根据这篇文章,下面哪种描述不正确?”从本文第一段、第二段第一句话,以及文章最后一句话可知A、B、D正确;第二段(obviously…its temperature)可知C不正确。
转载请注明原文地址:https://kaotiyun.com/show/HJrx777K
0

最新回复(0)