The Earth means many things to the people who live on it．A farmer thinks Earth is soil for growing vegetables and fruit．A person who makes roads thinks Earth is mountains of hard rock．A sailor thinks Earth is water as far as the eyes can see．The Earth is a big ball covered with water，rock and soil．The Earth is a planet．There are nine planets around the sun．Animals and plants live almost everywhere on the Earth．They can live on the Earth because it is not too far from the sun，or too close to the sun．Living things need the sun．The sun keeps them warm．

  Let's protect the Earth and the environment．People need to breath the fresh air．What should we do? These are the things we must do         

    A．Europe(欧洲)    B．Africa(非洲)

    C．Asia(亚洲)       D．Oceania(大洋洲)

    E．North America(北美洲)

    F．Antarctica(南极洲)

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