首页
登录
职称英语
The spectacular aurora light displays that appear in Earth’s atmosphere aroun
The spectacular aurora light displays that appear in Earth’s atmosphere aroun
游客
2025-03-30
1
管理
问题
The spectacular aurora light displays that appear in Earth’s atmosphere around the north and south magnetic poles were once mysterious phenomena. Now, scientists have data from satellites and ground-based observations from which we know that the aurora brilliance is an immense electrical discharge similar to that occurring in a neon sign.
To understand the cause of auroras, first picture the Earth enclosed by its magnetosphere, a huge region created by the Earth’s magnetic field. Outside the magnetosphere, blasting toward the earth is the solar wind, a swiftly moving plasma of ionized gases with its own magnetic filed. Charged particles in this solar wind speed earthward along the solar wind’s magnetic lines of force with a spiraling motion. The Earth’s magnetosphere is a barrier to the solar winds, and forces the charged particles of the solar wind to flow around the magnetosphere itself. But in the polar regions, the magnetic lines of force of the Earth and of the solar wind bunch together. Here many of the solar wind’s charged particles break through the magnetosphere and enter Earth’s magnetic field. They then spiral back and forth between the Earth’s magnetic poles very rapidly. In the polar regions, electrons from the solar wind ionize and excite the atoms and molecules of the upper atmosphere, causing them to emit aurora radiations of visible light.
The colours of an aurora depend on the atoms emitting them. The dominant greenish white light comes from low energy excitation of oxygen atoms. During huge magnetic storms oxygen atoms also undergo high energy excitation and emit crimson light. Excited nitrogen atoms contribute bands of colour varying from blue to violet. Viewed from outer space, auroras can be seen as dimly glowing belts wrapped around each of the Earth’s magnetic poles. Each aurora hangs like a curtain of light stretching over the polar regions and into the higher latitudes. When the solar flares that result in magnetic storms and aurora activity are very intense, aurora displays may extend as far as the southern regions of the United States.
Studies of auroras have given physicists new information about the behavior of plasmas, which has helped to explain the nature of outer space and is being applied in attempts to harness energy from the fusion of atoms. [br] The passage describes the magnetosphere as a barrier (Line 9) because______.
选项
A、its position makes it difficult to be observed from Earth
B、it prevents particles from the solar wind from easily entering Earth’s atmosphere
C、it increases the speed of particles from the solar wind
D、it is strongest in the polar regions
答案
B
解析
本题细节定位于第二段第三、四句话“Charged particles in this solar wind speed earthward along the solar wind’s magnetic lines of force with a spiraling motion.The Earth’s magnetosphere is a barrier to the solar winds,and forces the charged particles of the solar wind to flow around the magnetosphere itself”。由此可知,太阳风中的带电粒子快速地向地球移动,地球的磁层是一道阻隔太阳风的屏障,并迫使太阳风中的带电粒子绕地球的磁层流动。据此可知,地球的磁层可以阻隔太阳风中的粒子轻易地穿过大气层,因此选择B。
转载请注明原文地址:https://tihaiku.com/zcyy/4018583.html
相关试题推荐
Thepreservedfoodshouldretainpalatableappearance,flavor,andtexture,asw
With______exceptions,theformerpresidentdoesnotappearinpublicnow.A、rare
Thetemperatureoftheatmospherebecomescolderaselevationincreases.A、altit
Withinhoursofappearingontelevisiontoannouncetheendofconscription,
Withinhoursofappearingontelevisiontoannouncetheendofconscription,
Withinhoursofappearingontelevisiontoannouncetheendofconscription,
Withinhoursofappearingontelevisiontoannouncetheendofconscription,
Withinhoursofappearingontelevisiontoannouncetheendofconscription,
Withinhoursofappearingontelevisiontoannouncetheendofconscription,
Thepreservedfoodshouldretainpalatableappearance,flavor,andtexture,asw
随机试题
Likemostrecoveringoverachievers,Ihaveacomplicatedrelationshipwiths
BythetimeIlefttheschool,theprofessor______thatclassfortwoyears.A、h
Mind-controlledCarsA)AcarinGermanycanbesteeredw
Aresmarterkidssmartenoughtoavoidalcoholanddrugs?Fordecades,scien
计算简答题:根据所给材料回答问题。(凡要求作选择回答的问题,应将与所选选项对应的
公路供配电的下列明显特点,描述错误的是()A.公路沿线用电点多、用电负荷小
根据《建筑工程绿色施工评价标准》GB/T50640-2010,发生下列()事故
建筑工程安全防护、文明施工措施费用由()费组成。A.文明施工 B.环境保护
导墙是地下连续墙挖槽之前在槽口两侧修筑的埋深一般不小于1.5m的浅墙,其作用是有
A.选用合适的玻璃电极B.相对密度测定C.液体凝结为固体,在短时间内停留不变的最
最新回复
(
0
)