Propagation of sound Student activity Play

Protecting the environment Student activity Play

Protection against noise Slideshow Play

Protection of a house against heat loss Simulation Play

Protection of a house against heat loss Whiteboard exercise Play

Protection of a house against heat loss Student activity Play

Protection of food against bacteria – preservatives Whiteboard exercise Play

Protection of food against bacteria – preservatives Student activity Play

Protection of food – antioxidants Whiteboard exercise Play

Protection of food – antioxidants Student activity Play

Protection of the civilized environment Student activity Play

Protection of the civilized environment Whiteboard exercise Play

Protection of the human body against bacteria Whiteboard exercise Play

Protection of the human body against bacteria Student activity Play

Resonance Student activity Play

Resonance Student activity Play

Resonance Animation Play

Roles of efficient utilization and recycling in environmental protection Slideshow Play

Sacrificial protection Animation Play

Sacrificial protection Animation Play

Satellite telephones Student activity Play

Singing Student activity Play

Singing Simulation Play

Singing Whiteboard exercise Play

Sound Student activity Play