而究其灭绝原因,科学家提出了两种说法,一是climate,一是认为hunt。 Passage 2 The Formation of Early Earth早期地球的形成(首考新题) Passage 3 Colonial America and the Navigation Acts 殖民时期的美国和航海法案(重复2015.03.07) 先讲了早期英国殖民者对美洲的殖民引起了一些不满,因为收税过高且限制他们的一些...
The formation of Earth's core transformed conditions on Earth's surface.This is because it created the right conditions for development of the planet's magnetic field, which originates from movements in the outer layers of Earth's core. It had been known fora while that the magnetic field wa...
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 ...
One of the problems hindering understanding of the origin of life is that environmental conditions 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 hundred ...
Earth's surface had not only cooled sufficiently to form early crust (likely below 1,000°C) but even enough to allow for the presence of liquid water, which at modern atmospheric pressure would mean that temperatures had dropped below 100°C. However, at higher pressures this value is highe...
15:00 托福背景知识-天文学4-Classification of Stars 06:34 托福背景知识-天文学3-Star and Galaxy Formation in the Early Universe 06:39 托福背景知识-天文学2-A Big Bang and the Beginning of the Universe 15:00 托福背景知识-天文学1-Introduction to Astronomy 05:37 托福...
Within the molten interior, under the influence of gravity, different elements were sorted out by density. By about 40 million years after the formation of the solar system, most of the heavier metallic elements in the early Earth, such as iron and nickel, had sunk through the hot sludge ...
TF阅读真题第530篇Europe’s Early Sea Trade with Asia 00:50 TF阅读真题第528篇The Formation of Volcanic Islands 00:46 TF阅读真题第527篇Crafts in the Ancient Near East 00:44 TF阅读真题第526篇Modern Architecture in the United States 00:16 TF阅读真题第525篇Direct Species Translocation 00:...