Black Holes
Most scientists agree that black holes exist but are nearly impossible to locate. A black hole in the universe is not a solid object, like a planet, but it is shaped like a sphere (球體). Astronomers(天文學家) think that at the center of a black hole there is a single point in space with infinite (無限的) density (稠密). This single point is called a singularity (奇點). If the singularity theory is correct, it means that when a massive star collapses, all the material in it disappears into the singularity. The center of a black hole would not really be a hole at all, but an infinitely dense point.
Anything that crosses the black hole is pulled in by its great gravity.
Although black holes do exist, they are difficult to observe. These are the reasons.
• No light or anything else comes out of black holes. As a result, they are invisible to a telescope.
• In astronomical terms, black holes are truly. For example, a black hole formed by the collapse of a giant star would have an event horizon (視界) only 18 miles across.
• The nearest black holes would be dozens of light years away from Earth. One light year is about 6 trillion (萬億) miles. Even the most powerful telescopes could not pick out an object so small at such a great distance.
In 1994 the Hubble Space Telescope provided evidence that black holes exist. There are still answers to be found, however, so black holes remain one of the mysteries of the universe.
1. Black holes are part of space.
A. Right B. Wrong C. Not mentioned
2. Black holes exist but are difficult to observe.
A. Right B. Wrong C. Not mentioned
3. The center of a black hole is empty.
A. Right B. Wrong C. Not mentioned
4. The attraction of two large stars leads to gravity.
A. Right B. Wrong C. Not mentioned
5. The sun is the heaviest star in the universe.
A. Right B. Wrong C. Not mentioned
6. The nearest black holes are hundreds of light years away from us.
A. Right B. Wrong C. Not mentioned
7. The Hubble Space Telescope helps scientists to understand the nature of the universe.
A. Right B. Wrong C. Not mentioned
答案與解析
1. A。題干:黑洞是太空的一部分。利用space回到原文定位,很容易找到文中首段第三句和第二段第一句都有一致的信息。因此選擇A。
2. A。題干:黑洞是存在的但是不容易被觀察到。題干中的關(guān)鍵詞為difficult,用它回到原文定位,在首句能找到difficult的近義詞impossible。首句的意思是,黑洞確實存在,但很難定位(locate),與題意信息相符,故選A。
3. B。題干:黑洞的中心是空的。用中心詞the center來定位,首段倒數(shù)第二句有答案:其中心不是一個洞,由此證明中心不是空的,因此選擇B。
4. C。題干:兩顆大星體的相互吸引產(chǎn)生重力。用數(shù)字two和中心詞gravity(吸引力)回到原文定位,文章并沒有相關(guān)信息。故選擇C。
5. c。題干:太陽是宇宙最重的星體。用中心詞the sun回到原文定位,文章并未提及與太陽相關(guān)的信息。因此選擇C。
6. B。題干:離我們最近的黑洞有幾百光年遠。用中心詞nearest定位,原文倒數(shù)第二段有相關(guān)信息。但原文說的是“最近的黑洞離地球有幾十光年(dozens)遠”,而不是
“hundreds”。因此選擇B。
7. A。題干:Hubble太空望遠鏡幫助人們了解宇宙的本質(zhì)。由專有名詞the Hubble Space Telescope回到原文定位,不難發(fā)現(xiàn)相關(guān)信息在最后一段。原文信息與題干信息是一致的。
故選A。