Artificial or natural materialOnline version Try to guess if these materials are artificial o natural by Luz Álvarez Herrero 1 Cotton a Artificial b Natural 2 Clay pot a Artificial b Natural 3 Cork for wine bottles a Artificial b Natural 4 Leather a Artificial b Natural 5 Glass a Artificial b Natural 6 Wood -- a Artificial b Natural 7 Tire -- a Artificial b Natural 8 Paper a Artificial b Natural 9 Stones a Artificial b Natural 10 Plastic a Artificial b Natural 11 Precious gem a Artificial b Natural 12 Clothes a Artificial b Natural 13 wool -- a Artificial b Natural