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
7
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 supports which of the following statements about scientists’ understanding of auroras?
选项
A、Before advances in technology, including satellites, scientists knew little about auroras.
B、New knowledge about the fusion of atoms allowed scientists to learn more about auroras.
C、Scientists cannot explain the cause of the different colours in auroras.
D、Until scientists learn more about plasma physics, little knowledge about auroras will be available.
答案
A
解析
本题细节定位于第一段第一和第二句话“The spectacular aurora light displays that appear in Earth’s atmosphere…were once mysterious phenomena.Now, scientists have data from satellites and ground-based observations…in a neon sign”。由此可知,在地球南北磁极周围的大气层中出现的极光曾经是神秘的现象。如今,科学家们己经从卫星和地面观测得到的数据了解了这种现象。据此可知,在包括卫星在内的科技进步之前,科学家对极光现象所知甚少,因此选择A。
转载请注明原文地址:https://tihaiku.com/zcyy/4018585.html
相关试题推荐
ThespectacularauroralightdisplaysthatappearinEarth’satmospherearoun
ThespectacularauroralightdisplaysthatappearinEarth’satmospherearoun
With______exceptions,theformerpresidentdoesnotappearinpublicnow.A、rare
Ifallthevirusesontheplanetweretodisappear,aglobalcatastrophewould_
Withinhoursofappearingontelevisiontoannouncetheendofconscription,
Withinhoursofappearingontelevisiontoannouncetheendofconscription,
Withinhoursofappearingontelevisiontoannouncetheendofconscription,
Thereisariskthat________chemicalsmightbeblastedintotheatmosphere.A、d
Inproportionasthe_________betweenclasseswithinthenationdisappearstheh
Thepreservedfoodshouldretainpalatableappearance,flavor,andtexture,asw
随机试题
Readthememoandnotebelow.Completetheclaimform.Writewordorphrase(in
[originaltext]W:OK,John,youweresayingthatyoutaughtwritinginAmerica,
Chinesegovernmentencouragepeopletodrinkmilkandhopethat______.[br]The
下表为a、b两组不同土的颗粒组成成分及击实试验结果,请回答下列问题:(3)土的击
关于牙冠形态的生理意义,说法错误的是A.牙冠邻面突度可分散咬合压力 B.牙冠外
上市公司的下列事项,必须经股东大会特别决议通过的有( )。 Ⅰ.发行公司债券
按执行价格和标的资产市场价格关系分类,期权可分为()。A.看涨期权和看跌期权
下列选项中不属于患者道德义务的是()A.保持和恢复健康 B.接受医学生的
茵陈保肝作用的有效成分是A.茵陈烯酮B.β-蒎烯C.6,7-二甲氧基香豆素D.茵
根据《医疗废物管理条例》,医疗废物集中贮存、处置设施选址应当远离( )。A.交
最新回复
(
0
)