Dear Earthmen , I enjoy my stay on your interesting planet . I think I know the life on Earth now and I would like to tell you my ideas. First of all you live in boxes. Every morning you leave your boxes and get into smaller boxes on wheels . All these small boxes run around and around, and finally stop to rest. You leave these boxes on wheels and go to very large tall boxes. After resting all day, you get back in your little boxes. There you sit and look at very small _ boxes with moving pictures in them. There is only one thing I don't know. Some angry boys fought for a little round   ball. Everyone shouted  but they kept fighting. They were angry, because they had to stay in boxes all day, I think. Thank you for this chance  to get to know you. Yours, The man from Mars What's the main  idea of the letter?
To say goodbye to the Earthmen To tell the Earthmen what the Earth is like. To tell the Earthmen he doesn't like the Earth. To tell the Earthmen he is leaving the Earth soon.