enquête (2) Science (2) puits (1) enseignement (1) science (1) recherche (1) traitement (1) papier (1) information (1) Europe (1) éducation (1) dictionnaire (1) taux (1) Europe (1) Education (1) Development (1) Language (1) Specimens (1) Volunteers (1) Theater (1) Teaching--Aids and devices (1) Teaching (1) Teachers (1) Stairs (1) Speeches, addresses, etc (1) Research (1) Percentage (1) Paper (1) Materials (1) Lectures and lecturing (1)