求翻译：大气层又叫大气圈，地球就被这一层很厚的大气层包围着。大气层的成分主要有氮气，占78．1％；氧气占20．9％；氢气占0．93％；还有少量的二氧化碳、氦气、氖气、氪气、氙气和水蒸气。大气层的空气密度随高度而减小，越高空气越稀薄。大气层的厚度大约在1000千米以上，但没有明显的界限。整个大气层随高度不同表现出不同的特点，分为对流层、平流层、中间层、暖层和散逸层，再上面就是星际空间了。是什么意思？

Atmosphere known as the atmosphere, the Earth would be a thick layer of the atmosphere surrounded. The composition of the atmosphere is mainly nitrogen, accounting for 78.1%; oxygen accounted for 20.9%; hydrogen accounted for 0.93%; a small amount of carbon dioxide, helium, neon, krypton, xenon and

Atmosphere is called the atmosphere, the earth would be a very thick layer of the atmosphere surrounding. atmospheric composition is mainly nitrogen, accounting for 78.1 % and 20.9 % of oxygen, hydrogen accounts for 0.93 %; there is also a small amount of 2 carbon dioxide, helium, neon, krypton, and

Atmosphere and the atmosphere, the Earth is surrounded by a thick layer of the atmosphere. Components are mainly nitrogen atmosphere, accounting for 78. 1%; oxygen accounted for 20. 9%; hydrogen accounted for 0. 93%; there is also a small amount of carbon dioxide gas, helium, and neon, krypton, and