论文部分内容阅读
我们称地球为兰色行星。从空间拍摄的照片显示出一种特有景象,在可见的宇宙中其他任何地方都见不到的这种景象。水是地球上一切生命的基础。地球表面的三分之二是水。专家们算得,这
We call the Earth a blue planet. Photographs taken from space show a characteristic scene that is not visible anywhere else in the visible universe. Water is the foundation of all life on Earth. Two-thirds of the Earth’s surface is water. Experts count it