Introducing the Periodic Table
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High-Flying Airplanes
High-Flying Airplanes »

Les Cochons d'Inde et Autres Rongeurs / Guinea Pigs and Other Rodents
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A Nation Divided: Causes Of The Civil War
Causes Of The Civil War »

The Sun
Changes Its Position in Space, Therefore It Cannot Be Regarded as Being in a Condition of Rest »

Urals
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Moon
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Martin Luther King, Jr. Day
Commemorating the birthday of this champion of civil rights Martin LutherKing Jr. Day celebrates the accomplishments and efforts of Dr. King. Thiscompelling ... »

Non-Metals
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The Moon
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