The Earth's magnetic field is generated mainly by _. A. the movement of the outer core B. the rotation of the crust C. the presence of water on the surface D. the heat from the sun 相关知识点: 试题来源: 解析 A。解析:地球的磁场主要是由外地核中液态金属的流动产生的。地壳的旋转与...
解析 B 正确答案:B解析:本题考查考生的理解能力,根据原文内容“During a reversal,the main field weakens, almost vanish-es,and reappears with opposite polarity.”在反向运转时,主要的磁场就会减弱,几乎彻底消失,甚至重新出现相反的磁极。根据这句话可以知道,地球磁场开始向它的反方向改变,所以B比较符合题意。
A. begun to change in the opposite direction B. been weakening in strength for a long time C. caused the changes on the polarities D. misguided many a man and animal 相关知识点: 试题来源: 解析 B 正确答案:B 解析:文章第一段:《纽约时报》上周报道地球磁场严重减弱开始于150年前。磁场保护...
My grandfather was the only one in his family to come to the United States with his wife and children . He still had relatives living in Europe. When the first world war broke out, he lamented the fact if my uncle, his, only son had to go, it would be cousin fighting against ...
Preface The observation of the Earth's magnetic field is destined to play a crucial role in understanding the Earth system. The great potential of ground magnetic observations allows an impressive coverage of a diverse range of topics in the modern "magnetic world", in particular (i) development...
百度试题 结果1 题目Pigeons navigate less accurately when the earth’s magnetic field is ___. A. discovered B. dissuaded C. disturbed D. distracted 相关知识点: 试题来源: 解析 to check 反馈 收藏
The Earth's magnetic field is generated in the fluid region deep inside the Earth. Heat convection, buoyancy forces and planetary rotation cause the iron-rich fluid in the outer core to flow in a complex way and the movement of this electrical conductor through existing magnetic field generates...
According to the passage, the Earth’s magnetic field has ___. A.begun to change in the opposite directionB.been weakening in strength for a long timeC.caused the changes on the polaritiesD.misguided many a man and animal 相关知识点: 试题来源...
As the field originates in the Earth's molten core, the palaeomagnetic record is crucial to the understanding of both the origin and evolution of the geomagnetic field and the Earth's deep interior. 展开 关键词: geomagnetism geomagnetic observations spatial and temporal variations magnetic activity...
A. there would be no change on Earth B. the atmosphere would be gradually stripped away C. the Earth would stop rotating D. all living things would die immediately 相关知识点: 试题来源: 解析 B。解析:如果地球磁场突然消失,大气层会逐渐被剥离。地球磁场消失会对地球产生巨大影响,A选项错误。地球...