ASTRONOMY Celestial bodies Astronomical observation Astronautics EARTH Geography Geology Meteorology Environment VEGETABLE KINGDOM ANIMAL KINGDOM Simple organisms and echinoderms Insects and arachnids Crustaceans Mollusks Fishes Amphibians Reptiles Birds Rodents and lagomorphs Ungulate mammals Carnivorous mammals Marine mammals Primate mammals HUMAN BEING Human body Anatomy Sense organs FOOD AND KITCHEN Food Kitchen HOUSE Location Elements of a house Structure of a house Heating Plumbing Electricity House furniture DO-IT-YOURSELF AND GARDENING Do-it-yourself Gardening CLOTHING PERSONAL ADORNMENT AND ARTICLES Personal adornment Personal articles ARTS AND ARCHITECTURE Architecture Performing arts Music COMMUNICATIONS AND OFFICE AUTOMATION Communications Office automation TRANSPORT AND MACHINERY Road transport Rail transport Maritime transport Air transport Handling Heavy machinery ENERGY Geothermal and fossil energy Hydroelectricity Nuclear energy Solar energy Wind energy SCIENCE Chemistry Physics: electricity and magnetism Physics: optics Measuring devices Scientific symbols SOCIETY City Justice Economy and finance Education Religion Politics Safety Health SPORTS AND GAMES Games Track and field Ball sports Racket sports Gymnastics Combat sports Strength sports Precision and accuracy sports Winter sports Aquatic and nautical sports Cycling Motor sports Sports on wheels Outdoor leisure.