"This black t-shirt, which says “Silence = Death” with a pink triangle, symbolizes the struggle against AIDS.
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Grade Range:
5-12
Resource Type(s):
Reference Materials
Date Posted:
9/4/2013
Between the years 1790 and 1880 the U.S. Patent Office required both documentation and a three-dimensional working model to demonstrate each new invention submitted for a patent. The models helped to explain proposed innovations and compare them against similar inventions. In this online exhibiti
