英语听力：探索发现 科学新发现：我们的大气层-11（在线收听） |
The planet also began releasing oxygen, thanks to an ancient adoption of photosynthesis. A very ancestral primitive plant cell either engulfed or tried to digest or surrounded a cyanobaterium and instead of digesting it, it actually became an organ within the planet. So every bit of the oxygen, even if it’s coming from a plant that you use in your yard, is coming from an ancestor of a cyanobateria resident inside the plant. With the rise of oxygen, the air’s unique blend of gases was complete. The air we breathe has changed planet Earth, moulding its terrain and habitats. But as we continue our upward journey, we run into another vital substance, water.
The turbulent movement of our atmosphere carries water vapour around the globe. Powerful winds and violent storms smash our buildings and drown out fields. But without them the land would be bone dry. |
| 原文地址：http://www.tingroom.com/lesson/yytltsfx/2014/284451.html |