Labor (2) Ability (2) Trabajo (2) Aptitudes (2) Development (1) Childhood and youth (1) Specimens (1) Contaminated sediments (1) Origin (1) Wheat (1) Water (1) Walking (1) Vision (1) Temperature (1) Straw (1) Sorgo (1) Soils (1) Social sciences (1) Science (1) School children (1) Samples (Commerce) (1) Refuse and refuse disposal (1) Reformation (1) Quartz (1) Object-teaching (1) Miners (1) Methodology (1) Metals (1) Interpolation (1) Identification (1)