Costa Rica (3) Students (2) Solids (2) Refuse and refuse disposal (2) Perception (2) Evaluation (2) Education (2) Residuos (2) Evaluación (2) Estudiantes (2) Educación (2) Percepción (2) Sólidos (2) Conocimiento (2) génération (2) éducation (2) Greenhouse gases (1) Biodiversity (1) Weights and measures (1) Time (1) Teaching (1) Teachers (1) Storms (1) Sewage (1) Science (1) Schools (1) Quality of products (1) Production (Economic theory) (1) Problem solving (1) Organic wastes (1)