AN ice ball shoots across the night sky, lighting up its path along the way, like a flying sun.
Ancient humans were afraid of the sight of comets(彗星). Many cultures believed that comets were messages sent by gods, and people thought these messages were warning signs for bad behavior. But today science and technology give us a better understanding of comets.
Last week, comet Ison ended its million-year-long journey as it flew straight toward the sun, melting most of the comet. It was hoped that comet Ison would survive this trip around the sun. Because once it got near Earth, it would have produced a great show of lights for us.
In ancient times, the coming of comet Ison might have scared people. However, now we can track a comet’s journey in our solar system. We can also study what they’re made of. There is even a project to launch a spacecraft onto a comet to study them further.
Although from the sky they look like great giant fireballs, comets are a collection of gas, ice, dust and small rocks. As a comet goes into our solar system, the sun’s solar winds blow some of the dust and gas away, giving the comet a tail. The average size of comets is about 10 kilometers in diameter(直径). But amazingly, their tails can be 150 kilometers long! Comet Ison’s diameter was about 5 kilometers.
Today, people don’t fear comets as much as they did before. Western countries have even developed and old tradition. When people see a comet or meteoroid(流星) shooting across the sky, they call it a shooting star, People who get the chance to see one get to make a wish. It is a tradition that lives on today.
小题1:In ancient times, people thought comets were _____.
A．warning signs sent by gods
B．lucky signs for good behavior
C．great shows of lights
D．flying suns小题2:We can tell from the third paragraph that comet Ison ___.
A．finished its long journey to Mars
B．survived its trip around the sun
C．has reached the Earth
D．was melted by the sun小题3:When a comet travels near the sun, some of the __ will be blown away by the solar winds.
A．gas and dust
B．ice and rocks
C．dust and rocks
D．rocks and tail小题4:According to the last paragraph, what tradition lives on today?
A．Being scared by comets and meteoroids.
B．Making a wish when seeing a shooting star
C．Launching spacecrafts onto comets to study them further.
D．Having a better understanding of comets
小题1:A
小题2:B
小题3:A
小题4:B
题目分析：这篇短文主要介绍人们对彗星的认识。文章介绍，古时候人们害怕看见彗星，认为这是不祥的征兆。现在，人类已经开始对其进行深入的研究，并且不再像以前那样害怕彗星了。西方国家甚至把它发展成为一个传统，即看见流星划过天空，要许下一个心愿。
小题1:细节理解题。根据短文第二段Ancient humans were afraid of the sight of comets(彗星). Many cultures believed that comets were messages sent by gods, and people thought these messages were warning signs for bad behavior的描述可知，古时候人们认为彗星是上帝发送的警示标志。故选A。
小题2:细节理解题。根据短文第三段It was hoped that comet Ison would survive this trip around the sun的描述可知应选B。
小题3:细节理解题。根据短文As a comet goes into our solar system, the sun’s solar winds blow some of the dust and gas away, giving the comet a tail.的描述可知，太阳风会吹走一些气体和尘土。故选A。
小题4:细节理解题。根据短文最后一段When people see a comet or meteoroid(流星) shooting across the sky, they call it a shooting star, People who get the chance to see one get to make a wish. It is a tradition that lives on today的描述可知，看见流星就许愿的传统至今流传。故选B。