temps (durée) (1) test (1) pierre (1) saison (1) sable (1) roche (1) fleuve (1) projet (1) musée (1) matériau (1) industrie (1) âge (1) Development (1) Implements (1) Antiquities, Prehistoric (1) Tools (1) Time (1) Stone (1) Spring (1) Soils (1) Science (1) Scarcity (1) Sand (1) Red (1) Quartz (1) Probabilities (1) Prehistoric peoples (1) Industries (1) Estimates (1) Dates (Fruit) (1)