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    Is there life on other planets? There are seven other planets in our ____ system, but ____ of them has an environment like that of the ____. Spaceships   from the earth have done surveys of the other planets, but they have not found any life there. Why has no one from other planets tried to ____ with us? It is true that scientists have not discovered life on other planets in the ____ yet, but some scientists believe that they will find it some day.