• 8 Videos, Slides, Films

• 7 History
• 5 Technology
• 1 Air conditioning
• 1 Artificial intelligence
• 1 Diplomacy
• 1 Drinking water
• 1 Electric lighting
• 1 Evolution
• 1 Foreign relations
• 1 Glass
• 1 Human beings
• 1 Industrial revolution
• 1 Inventions
• 1 Lighting
• 1 Public health
• 1 Recording and reproducing
• 1 Refrigeration and refrigerating machinery
• 1 Sanitation
• 1 Sound
• 1 Technology and civilization
• 1 Time measurements

• 6 Films Media Group
• 1 Barro, Andri
• 1 Copp, Duncan
• 1 Docherty, Neil
• 1 Fanning, David
• 1 Five O'Clock Films
• 1 Lyman, Will, 1948-
• 1 Michaels, Kasper, 1967-
• 1 WGBH (Television station : Boston, Mass.)
• 1 Watkins, Ed (Edward)

• 8 English

• 2 United States
• 1 China
• 1 Earth (Planet)

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