Earth - the third planet (planet earth) from the Sun. The only planet in the Solar system that has life .Although it is possible that life was once on Venus and Mars may have at the moment on the satellites of giant planets: Europe, Ganymede, Enceladus and Titan . The earth is a unique planet!It is the only planet on which life is possible.If the Earth were slightly farther from the Sun it would be cold,and if closer its temperature was so hot that her life would not exist. я посчитала тут 70 с чем то. я думаю столько хватит