Polyurethane is a type of rubber invented by a German inventor called Bayer in 1930s. Polyurethane is used, among other things, to make skating wheels
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Kavitha Komatineni 4th Grade(2007-2008) |
"A Great Resource for 4th Grade"
Are you a Teacher (or otherwise) interested in collaborating to develop content for 4th graders?? Click here to see details
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