职称英语 (12)
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I am feeling a lot more healthy than I was.
Things have changed a lot since I was a child.
He was so greatly attracted by the beauty of the Xixi Wetland that he decided to visit there again.
Take some spare clothes in case you get wet.
She is a highly successful teacher.
Rodman met with Tony to try and settle the dispute over their contract.
Knowing that I had been out of work now,they were unwilling to lend me money.
The expedition reached the summit at 10:30that morning.
The police took fingerprints and identifiend the body.
It is highly unlikely that she will arrive today.
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No one can prevent me from hunting for a bright future.
That performance was pretty impressive.
He is determined to consolidate his power.
The two girls look alike.
Will you please call my husband as soon as possible?
This gold mine was discovered by accident.
John is crazy about pop music.
The test produced disappointing results.
My younger sister is a fascinating girl.
共用题干
Black HolesMost 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（球体）. Astronomers（天文学家）think that at the center of a black hole there is a single point in space with infinite（无限的）density（稠密）.This single point is called a singularity（奇点）.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 tiny.For example,a black hole formed by the collapse of a giant star would have an event horizon（视界）only 18 miles across.The nearest black holes would be dozens of light years away from Earth.One light year is about 6 trillion（万亿）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.
