共用题干 New Comet FoundThere's a newfound comet closing in on the sun,and when...

问题共用题干 New Comet Found

There's a newfound comet closing in on the sun,and when it gets here in 2013,you may be able to see it with your naked eye.
Astronomers stumbled upon the icy interloper on June 5 while searching for potentially hazardous asteroids（小行星）.Equipped with the world's largest digital camera , the University of Hawaii's Pan-STARRS team snagged a faint image of the odd object while it was more than 700 million miles away , between the orbits of Jupiter（木星）and Saturn（土星）.
"Almost everything we find is an asteroid,but this object was suspicious,"said Richard Wainscoat,co-discoverer of the comet and an astronomer at the University of Hawaii."Unlike asteroids, which appear point-like in images,the telltale sign that gave it away was its fuzzy appearance."
By March 2013 the comet,named C/2011 L4(PANSTARRS),is expected to come within 30 million miles of the sun一closer even than the innermost（最深处）planet, Mercury（水星）.
When the comet makes its closest approach to the sun,most of its ices will vaporize,adding to its hazy envelope of gas and dust and producing the familiar tail. This denser envelope,or coma, should boost the comet to peak brightness,making it potentially visible to the naked eye low in the western horizon just after sunset.
While there is no danger of collision with Earth,preliminary calculations of the comet's orbit show that this may be its first and final trip through the solar system."It may be coming around the sun for the first and only time,only to be ejected from the solar system,never to return,"Wainscoat said."Since we don't have a lot of data on it,we really don't know the orbit well enough right now, and it will take up to two months of observations to find out."
Astronomers believe C/2011 L4 may be a runaway from the Oort cloud（奥尔特云）,a reservoir of billions of hibernating（蛰伏）comets that orbits about 100,000 times farther than the distance between Earth and the sun.
The fact that it's going around the back of the sun from our point of view may ultimately affect the comet's visibility,but a lot will depend on how close the body actually gets to the sun.Also, whether the comet is north or south of the sun when it reaches peak brightness will determine which hemisphere on Earth gets the better view.

选项 Astronomers gets many details about the solar system. A:Right B:Wrong C:Not mentiond

答案 B

解析题干意思为：天文学家用肉眼发现了新彗星。从文中第二段第二句可以找到出处：Equipped with the world's largest digital camera…借助世界上最大的数字摄像机……显然题干意思与原文相悖，所以是错误的。
题干意思为：新彗星是由汞构成的。第五段第一句中：When the comet makes its closest approach to the sun , most of its ices will vaporize…当彗星靠近太阳时，大部分冰会融化。可以推测出，彗星的主要构成是冰，而不是汞。所以该项错误。
题干意思为：在不断接近太阳的过程中，彗星的冰会融化。第五段第一句中：When the comet makes its closest approach to the sun , most of its ices will vaporize…当彗星靠近太阳时，大部分冰会融化……可以推断出题干与原文意思一致。
题干意思为：天文学家掌握了太阳系的很多信息。通读全文，提到太阳系的只有第六段：Since we don't have a lot of data on it…由于我们并未掌握太多的信息……由此可知，题干意思与该句表达冲突，所以选择B。
题干意思为：北半球能更好地观测彗星。文中最后一段最后一句：Also, whether the comet is north or south of the sun when it reaches peak brightness will determine which hemisphere on Earth gets the better view．当彗星达到最亮值时，它在太阳的南面还是北面将决定在地球哪个半球能够更好地观测彗星。可以推知，哪一个半球观测效果好取决于彗星的位置，所以题干表述错误。
题干意思为：理查德·文斯考特是彗星的发现者之一。文中第三段第一句后半句：…co-discoverer of the comet and an astronomer at the University of Hawaii.……是彗星的共同发现者之一，也是夏威夷大学的天文学家。可以推知，题干与该句意思一致。
题干意思为：C/2011 L4彗星将在2013年撞上地球。文中第六段第一句指出：While there is no danger of collision with Earth…虽然不存在撞击地球的危险性……可以推知，题干意思与原文意思相悖。

共用题干 New Comet FoundThere's a newfound comet closing in on the sun,and when...

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