As the dust grains were falling down into the solar disk,they began to collide and stick together, especially once they were in the disk. ▉Clumps formed, then bigger clumps, until soon the space that is now occupied by the inner planets (Mercury, Venus, Earth, and Mars) was littered wi...
• The earth was just a cloud of dust after the “Big Bang”. The earth exploded(explode) loudly with fire and rock. They were in time to produce many things, which were to make the earth’s atmosphere. As the earth cooled down, water began to appear on its surface. It allowed ...
–Atmosphere of the moon –How Far is the Moon? –Every mission to the moon In 2012, researcher Robin Canup, of the Southwest Research Institute in Texas, proposed that Earth and the moon formed at the same time when two massive objects five times the size of Mars crashed into each othe...
Para.1Para.2Para.3Para.4Para.5AtheoryabouthowtheuniversewasformedTheformation(形成)oftheearthTheimportanceofwaterforlifeThedevelopmentofplantsandanimalsThearrivalofhumansandtheireffectsontheearthPart1:ThedevelopmentoftheearthPart2:Thedevelopmentoflife.Howmanypartscanthepassagebedividedinto? Part1(1~3):Thede...
have survived in the Archean atmosphere, which lacked oxygen and an ozone layer. Nevertheless, it is widely understood that it was during this time that most primordial life began to take form, though some scientists argue that many lifeforms may have occurred even sooner during the late Hadean...
Researchers at the Australian National University (ANU) found that ocean water cycled up to 2,900 kilometers below the Earth's surface, well in excess of the previously-though 100 kilometers, throwing into doubt previous theories of how oceans and the atmosphere formed. One theory previously tho...
in the solar nebula, out of Earth's interior. Erupting in great clouds from volcanoes-a process called "out gassing”一the water vapor condensed and rained out of the atmosphere. Gradually, according to this idea, over hundreds of millions or even billions of years, the oceans were created....
导言“新编跨文化交际英语教程·教师用书”主要是为使用“新编跨文化交际英语教程”教 师配套的教学指南。“新编跨文化交际英语教程”是在原有“跨文化交际英语教程”的基础上 经过全面、系统修订而成,我们对全书做了较大的更新和完善,调整和增补了许多材料,力 求使其更具时代性,更适合教学实际和学生需求。 为了进...
Around 2.5 billion years ago, oxygen appeared. As more sunlight was able to penetrate the earth’s atmosphere, it brought the first opportunity for photosynthesis. Oxygen formed made by simple blue-green algae known as cyanobacteria. They are thought to be the first oxygen creating organisms to ...
have survived in the Archean atmosphere, which lacked oxygen and an ozone layer. Nevertheless, it is widely understood that it was during this time that most primordial life began to take form, though some scientists argue that many lifeforms may have occurred even sooner during the late Hadean...