"Popular Mechanics for Kids" (a series of TV shows that are also on DVDs) explains many concepts to kids in a fun and appropriate way for kids. They have an episode on "Air Transport", "Spaceships", "Robots", "Aircraft Carriers", and a lot more. You might get some good ideas on how to explain things at the kid's level about what you do from these videos.
http://www.discoverykids.ca/shows/pmk/episodes.asp
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"Popular Mechanics for Kids" (a series of TV shows that are also on DVDs) explains many concepts to kids in a fun and appropriate way for kids. They have an episode on "Air Transport", "Spaceships", "Robots", "Aircraft Carriers", and a lot more. You might get some good ideas on how to explain things at the kid's level about what you do from these videos. http://www.discoverykids.ca/shows/pmk/episodes.asp