but the energy from the intense early impacting by objects from space had pushed temperatures up well above the melting temperature of rocks. Still, research has demonstrated that as early as about 4.4 billion years ago, Earth's surface had not only cooled sufficiently to form...
托福阅读真题第47篇TheCoolingofEarlyEarth 地球形成于 46 亿年前,在最初的 50 到 1 亿年中,它是一个沸腾的液态岩石球,没有永久地壳(最坚硬的外层)。地球最早阶段的一个重要事件被称为分化事件,这完全改变了地球最初均匀的组成。它发生在大约 45 亿年前,当时地球已经变得足够大,压力足以推动内部温度超过 1,...
然后,密度更大(富含金属)的物质下沉到地球的中心,密度较小的(岩石)物质向地表上升。下沉的密集物质形成了地球的镍铁核心,也就是地球的内部 3500 公里左右。升起的较轻的物质形成了密度较低的岩石地幔,即地球” 地核的形成改变了地表条件。是因为它为地球的发展创造了合适的条件磁场,它起源于地球核心外层的运动。早...
所属专辑:托福阅读 音频列表 1 TF048-The Commercialization of Agriculture in the United States 64 2023-03 2 TF047-The Cooling of Early Earth 39 2023-03 3 TF046-The Decline of the Arctic Fox in Scandinavia 31 2023-03 4 TF045-The Documentary Film in the United States ...
14 TF047-The Cooling of Early Earth 00:18 TF046-The Decline of the Arctic Fox in Scandinavia 00:19 TF045-The Documentary Film in the United States 00:16 TF044-British Agriculture 00:14 TF043-Herbivores on the Serengeti Plain 00:14 TF042-The Evolution of Plant Roots 00:13 TF051-E1 ...
5.Select the TWO answer choices that, according to paragraph 2, describe effects that would have resulted from the impacts of meteorites on early Earth. To receive credit, you must select TWO answers. A. Materials beneath the surface became molten. ...
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One of the problems hindering understanding of the origin of life is that environmental cond巾ons on early Earth are not known with any certainty. It is possible to make only reasoned estimates. For example, for some fairly long period of time after formation, perhaps as much as several hundr...
Professor: OK, researchers have deduced that since we don't have proof of any intact rocks from before then, that earth started cooling down after about five hundred million years, rocks earlier than that, would’ve been obliterated by the fire and heat. It makes sense, right?
Scientists think that climate warming may slow down circulation, while cooling may speed it up, but these responses are not well understood. Evaporation from the ocean also supplies the precipitation that creates fields of snow and ice at high latitudes. Snow and ice coverage change the ...