Question

    Scientists have discovered a "monster black hole" so massive that, in theory, it shouldn't exist

It’s a stellar black hole---the type that forms after stars die, collapse, and explode. Researchers had previously believed that the size limit was no more than 20 times the mass of our sun because 8S these stars die, they lose most of their mass through explosions that expel matter and gas swept away by stellar winds

This theory has now been toppled by LB-1, the newly discovered black hole. Located about 15.000 light years away, it has a mass 70 times greater than our sun, according to a press release from the Chinese Academy of Sciences.

The findings were published by Chinese researchers in the journal Nature on Wednesday.

"Black boles of such mass should not even exist in our galaxy, according to most of the current models of stellar evolution," said Liu Jifeng, head of the team that made the discovery. "LB-1 is twice as massive as what we thought possible. Now theorists will have to take up the challenge of explaining its formation."

Scientists are now scratching their heads at how LB-1 got so huge.

The Chinese team has proposed a number of theories. LB-1' sheer size suggests that it “was not formed from the collapse of only one star," the study said--- instead, it could potentially be two smaller black holes orbiting each other.

Another possibility is that it formed from “fallback supermova.” This is when a supernoma---the last stage of an exploding star---ejects material during the explosion, which then falls back into the supernova, creating a black hole.

This fallback formation is theoretically possible, but scientists have never been able to prove or observe it. If this is how LB-1 formed, then we may have "direct evidence for this process” for the first time, the study said.

There are several types of black holes and stellar black holes like LB-1 are on the smaller side, according to NASA. Supermassive black holes are much bigger---they can be billions of times the mass of our sun,

Scientists believe supermassive black holes may be connected to the formation of galaxies, as they often exist at the center of the mass star stems but it is still not clear exactly how, or which form first.

1.Why does the writer write the article?

A.To report the great achievement Chinese scientists have made in black hole theory,

B.To inform the readers of the basic knowledge about the black hole,

C.To share with the readers the new development of the black hole discovery,

D.To demonstrate the significance of discovering new black holes for science.

2.Which of the following about LB-1 is true to the passage?

A.It is the biggest black hole ever discovered,

B.It lost only a small part of its mass through explosion.

C.It couldn't have been formed from the collapse of one star,

D.Its discovery may lead to some breakthrough in the “fallback formation theory".

3.Which of the following is right according to the passage?

A.If the sun in our galaxy dies some of its mass will be taken away by stellar winds.

B.A massive supernova will be formed and then exploded if the sun in our galaxy dies.

C."The Milky Way" was formed after a supermassive black hole collapsed and exploded.

D.If “the Milky Way" dies, a supermassive black hole will be formed after its death.

Answer

1.C

2.D

3.A

【解析】

这是一篇新闻报道。短文报道科学家们已经发现了一个“巨型黑洞”，其质量之大，在理论上是不应该存在。但这个理论现在已经被新中国科学家发现的黑洞LB-1所推翻。科学家们现在正绞尽脑汁研究LB-1是如何变得如此巨大的，并介绍了几种可能性的理论。

1.推理判断题。由第一段“Scientists have discovered a "monster black hole" so massive that, in theory, it shouldn't exist.”可知，科学家们已经发现了一个“巨型黑洞”，其质量之大，在理论上是不应该存在。由“This theory has now been toppled by LB-1, the newly discovered black hole. Located about 15.000 light years away, it has a mass 70 times greater than our sun, according to a press release from the Chinese Academy of Sciences.”可知，但这个理论现在已经被新中国科学家发现的黑洞LB-1所推翻。根据中国科学院的一份新闻稿，它位于15000光年之外，质量是太阳的70倍。所以判断出作者写这篇文章的目的是与读者分享黑洞发现的新进展，故选C项。

2.细节理解题。由倒数第三段“If this is how LB-1 formed, then we may have "direct evidence for this process” for the first time.”可知，如果这就是LB-1的形成过程，那么我们可能首次有了“这一过程的直接证据”。所以LB-1这一发现可能会给“后援形成理论”带来一些突破。故选D项。

3.细节理解题。由第一段“because 8S these stars die, they lose most of their mass through explosions that expel matter and gas swept away by stellar winds.”可知，因为这些恒星会死亡，它们大部分质量因爆炸而损失，恒星风会把爆炸释放出来的物质和气体吹走。所以如果我们星系中的太阳死亡，它的一部分质量会被恒星风吹走。故选A项。