| 释义 |
地球dìqiú太阳系九大行星之一,按离太阳由近而远的次序计为第三颗,形状像球而略扁,赤道半径约6,378.2公里,极半径约6,356.8公里,自转一周的时间是一昼夜,绕太阳一周的时间是一年。周围有大气层包围,表面是陆地和海洋,有人类和动植物等生存。有一个卫星(月球)。{the earth; in terms of distance from the sun, the third of the nine planets of the solar system, shaped like a slightly flattened ball. The earth's equatorial radius is about 6,378.2 km., its polar radius about 6,356.8 km. One rotation of the earth takes a day and a night, and one revolution around the sun takes a year. Surrounded by atmosphere and covered by land and oceans, the earth is inhabited by human beings, animals and plants. It has one natural satellite, the moon.} |