Passage 4
The mysterious spokes in Saturn’s （土星） rings may be created by massive thunderstorms in the planet’s atmosphere. If the theory is right, these faint features are the signature of awesome events: lightning strokes ten thousand times more energetic than those on Earth, releasing beams of electrons that surge up from Saturn’s surface to whack into the rings and blast out jets of electrically charged dust.
The idea, proposed by Geraint Jones of the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany, and his colleagues in Geophysical Research Letters, remains speculative. No one has ever seen storm-induced electron beams on Saturn. But the researchers say that the theory would explain some puzzling features of the spokes, and that it fits with what is known about the effects of thunderstorms on Earth.
The spokes of Saturn’s rings were first discovered by the Voyager I and II spacecraft when they passed close to the gas giant planet in 1980 and 1981. The spokes are “a very complex phenomenon, and a difficult thing to untangle”, says Carolyn Porco of the Space Science Institute in Boulder, Colorado, who was the first person to work on these mysterious features back in the Voyager days.
The spokes appear as bright or dark streaks about 100 km wide and up to 20,000 km long that cross the rings, making them look as though they have been smeared by a giant finger. They are transient, building up over a period of a few hours and then disappearing again several hours later. And they aren’t always there at all: between 1998 and 2004, when NASA’s Cassini spacecraft reached the planet, there was no sign of any. Spokes reappeared in September 2005, when Cassini took snapshots of them.
Researchers agree that the spokes are made of dust grains that have become electrically charged and are pushed up out of the rings in long streamers by electrostatic repulsion. But they don’t know what causes the charging.
One theory is that this happens when meteorites plough into the rings and whip up a cloud of charged plasma, which then charges up the rings’ dust particles. But this, says Jones, can’t explain why the spokes build up gradually—it’s implausible that several meteorites would strike the rings in the same place in close succession.
An alternative explanation is based on the way that thunderstorms on Earth can generate electron beams in the upper atmosphere. While regular lightning bolts travel between clouds and the ground below, high-energy particles streaming from space called cosmic rays can trigger electron discharges above the clouds. These electrons stream outwards into space along the field lines of the Earth’s magnetic field. This can produce flashes of gamma rays as well as glowing atmospheric features called sprites.
Thunderstorms are also known to happen within the thick atmosphere of Saturn, and Jones and colleagues say that these are likely to have the same effect—cosmic rays coming in towards Saturn should likewise form outgoing electron beams that could hit the rings, charging up dust grains.
1. Which of the following statements may be the author’s view?
2. It was Carolyn Porco who first worked on ________.
3. Why didn’t Cassini get the sign of spokes when it reached Saturn between 1998 and 2004?
4. What is Jones’ view on several meteorites?
5. It is believed that thunderstorms ________.
问题1选项
A.Thunderstorms have great destructive force.
B.Saturn’s spokes may be made by lightning.
C.Saturn exploration will be continued.
D.Spokes are a common phenomenon in galaxy.
问题2选项
A.the mysterious phenomena in the universe
B.the features of space science
C.voyager spacecraft
D.the spokes of Saturn’s rings
问题3选项
A.Because the spokes are transient.
B.Because the spokes are too tiny.
C.Because Cassini was not close enough to Saturn.
D.Because the spokes were too dark to be seen at that time.
问题4选项
A.They are unlikely to strike the rings in the same place in close succession.
B.They plough into the rings of Saturn.
C.They charge dust particles around the rings of Saturn.
D.They create a cloud of charged plasma and appear as bright or dark streaks.
问题5选项
A.can create flashes of gamma rays
B.may happen within the thick atmosphere of Saturn
C.may interfere with the magnetic field of Saturn
D.can blast out jets of electrically charged dust
第1题:B
第2题:D
第3题:A
第4题:A
第5题:B
第1题:
【选项释义】
Which of the following statements may be the author’s view? 以下哪项陈述可能是作者的观点？
A. Thunderstorms have great destructive force. A. 雷暴具有巨大的破坏力。
B. Saturn’s spokes may be made by lightning. B. 土星的辐条可能是闪电造成的。
C. Saturn exploration will be continued. C. 土星探测将继续进行。
D. Spokes are a common phenomenon in galaxy. D. 辐条是星系中的一种常见现象。
【考查点】推理判断题。
【解题思路】根据B选项关键词lightning可以定位到文章第一段第一、二句The mysterious spokes in Saturn’s rings may be created by massive thunderstorms in the planet’s atmosphere. If the theory is right, these faint features are the signature of awesome events: lightning strokes ten thousand times more energetic than those on Earth（土星环上神秘的辐条可能是由土星大气层中的巨大雷暴造成的。如果这一理论是正确的，那么这些微弱的特征就是可怕事件的标志：比地球上的闪电能量高出一万倍的闪电），说明作者认为闪电可能与土星环的辐条有关。因此B选项“土星的辐条可能是闪电造成的。”正确。
【干扰项排除】
A选项“雷暴具有巨大的破坏力。”，C选项“土星探测将继续进行。”和D选项“辐条是星系中的一种常见现象。”在文中均没有提及，属于无中生有。
第2题:
【选项释义】
It was Carolyn Porco who first worked on ________. 最早研究________的是卡罗琳·波科。
A. the mysterious phenomena in the universe A. 宇宙中的神秘现象
B. the features of space science B. 太空科学的特点
C. voyager spacecraft C. 旅行者号飞船
D. the spokes of Saturn’s rings D. 土星环的辐条
【考查点】事实细节题。
【解题思路】根据题干关键词Carolyn Porco可以定位到文章第三段第二句The spokes are “a very complex phenomenon, and a difficult thing to untangle”, says Carolyn Porco of the Space Science Institute in Boulder, Colorado, who was the first person to work on these mysterious features back in the Voyager days.（科罗拉多州博尔德空间科学研究所的卡罗琳·波科说，辐条是“一种非常复杂的现象，也是一种难以解开的东西”，她是旅行者号时代研究这些神秘特征的第一人。），说明是卡罗琳·波科首次研究了土星环的辐条。因此D选项“土星环的辐条”正确。
【干扰项排除】
A选项“宇宙中的神秘现象”，虽然土星环是一种神秘现象，但文中没有提到她研究的是整个宇宙中的神秘现象，属于过度推断；
B选项“太空科学的特点”在文中没有提及，属于无中生有；
C选项“旅行者号飞船”，虽然文中提到她在旅行者号时代开始研究，但并没有说她研究的是旅行者号飞船本身，属于曲解原文。
第3题:
【选项释义】
Why didn’t Cassini get the sign of spokes when it reached Saturn between 1998 and 2004? 为什么卡西尼号在1998年至2004年间到达土星时没有发现辐条的迹象？
A. Because the spokes are transient. A. 因为辐条是短暂的。
B. Because the spokes are too tiny. B. 因为辐条太小。
C. Because Cassini was not close enough to Saturn. C. 因为卡西尼号离土星不够近。
D. Because the spokes were too dark to be seen at that time. D. 因为辐条太暗，当时无法看到。
【考查点】事实细节题。
【解题思路】根据题干关键词Cassini可以定位到文章第四段第二、三句They are transient, building up over a period of a few hours and then disappearing again several hours later. And they aren’t always there at all: between 1998 and 2004, when NASA’s Cassini spacecraft reached the planet, there was no sign of any.（它们是短暂的，在几个小时内形成，然后在几个小时后再次消失。而且它们并不总是在那里：在1998年到2004年，当美国宇航局的卡西尼号宇宙飞船到达土星时，没有任何迹象表明它们存在。），说明辐条是短暂现象，所以卡西尼号没有发现。因此A选项“因为辐条是短暂的。”正确。
【干扰项排除】
B选项“因为辐条太小。”，C选项“因为卡西尼号离土星不够近。”和D选项“因为辐条太暗，当时无法看到。”在文中均没有提及，属于无中生有。
第4题:
【选项释义】
What is Jones’ view on several meteorites? 琼斯对几块陨石的看法是什么？
A. They are unlikely to strike the rings in the same place in close succession. A. 它们不太可能接二连三地在同一地点撞击星环。
B. They plough into the rings of Saturn. B. 它们钻进了土星环。
C. They charge dust particles around the rings of Saturn. C. 它们会给土星环周围的尘埃粒子充电。
D. They create a cloud of charged plasma and appear as bright or dark streaks. D. 它们形成带电等离子体云，并呈现出或明或暗的条纹。
【考查点】事实细节题。
【解题思路】根据题干关键词Jones’ view on several meteorites可以定位到文章第六段最后一句But this, says Jones, can’t explain why the spokes build up gradually—it’s implausible that several meteorites would strike the rings in the same place in close succession.（但琼斯说，这无法解释为什么辐条会逐渐增加——几颗陨石接二连三地撞击星环的同一个地方是难以置信的。），说明琼斯认为几颗陨石不太可能在接近同一地点连续撞击。因此A选项“它们不太可能接二连三地在同一地点撞击星环。”正确。
【干扰项排除】
B选项“它们钻进了土星环。”是文中提到的另一种理论，不是琼斯的观点，属于张冠李戴；
C选项“它们会给土星环周围的尘埃粒子充电。”是文中提到的另一种理论，不是琼斯的观点，属于张冠李戴；
D选项“它们形成带电等离子体云，并呈现出或明或暗的条纹。”是对现象的描述，不是琼斯的观点，属于出处错位。
第5题:
【选项释义】
It is believed that thunderstorms ________. 据说雷暴________。
A. can create flashes of gamma rays A. 可以产生伽马射线闪光
B. may happen within the thick atmosphere of Saturn B. 可能发生在土星厚厚的大气层中
C. may interfere with the magnetic field of Saturn C. 可能会干扰土星的磁场
D. can blast out jets of electrically charged dust D. 可以喷射出带电尘埃
【考查点】事实细节题。
【解题思路】根据题干关键词thunderstorms可以定位到文章第八段第一句Thunderstorms are also known to happen within the thick atmosphere of Saturn（众所周知，土星厚厚的大气层中也会发生雷暴），说明雷暴可能发生在土星的厚大气层中。因此B选项“可能发生在土星厚厚的大气层中”正确。
【干扰项排除】
A选项“可以产生伽马射线闪光”和D选项“可以喷射出带电尘埃”是雷暴释放的电子束带来的效应，而不是对雷暴本身的描述，属于曲解原文；
C选项“可能会干扰土星的磁场”在文中没有提及，属于无中生有。
