Categories (words):
Astronomy
Celestial bodies
Planets, satellites and plutoids
Astronomical observation
Constellations of the southern hemisphere
Constellations of the northern hemisphere
Celestial coordinate system
Astronautics
International space station
Earth
Geography
Configuration of the continents
Geology
Meteorology
Profile of the earth's atmosphere
International weather symbols
Meteorological measuring instruments
Environment
Structure of the biosphere
Natural greenhouse effect
Enhanced greenhouse effect
Selective sorting of waste
Plant kingdom
Plant life
Simple plants
Plant
Industrial use
Animal kingdom
Evolution of life
Origin and evolution of species
Biological classification
Primitive animals
Examples of primitive animals
Molluscs
Crustaceans
Insects and arachnids
Cartilaginous fishes
Examples of cartilaginous fishes
Bony fishes
Amphibians
Reptiles
Birds
Examples of aquatic birds and waders
Examples of terrestrial birds
Insectivorous mammals
Examples of insectivorous mammals
Rodens
Lagomorphs
Ungulate mammals
Examples of ungulate mammals
Carnivorous mammals
Examples of carnivorous mammals
Merine mammals
Examples of marine mammals
Primates
Flying mammals
Examples of flying mammals
Marsupial mammals
Examples of mursupial mammals
Human being
Human body
Anatomy
Sense organs
Food and kitchen
Supply
Plant-derived food
Animal-based food
Processed foods
Food business
Kitchen
Cutlery
Kitchen equipment
House
Location
Elements of a house
Structure of a house
Heating
Air conditioning
Air conditioning appliances
Plumbing
Pedestal-type cesspit pump
Electricity
House furnishings
Do-it-yourself and gardening
Materials
Carpentry
Measuring and marking tools
Gripping and tightening tools
Plumbing and masonry
Electricity
Soldering
Painting unkeep
Ladders and stepladders
Pleasure garden
Gardening materials
Tools for loosening the earth
Pruning and cutting tools
Seeding and planting tools
Snow removal
Clothing
Textiles
Historical clothes
Examples of ancient costumes
Examples of traditional clothing
Men's clothing
Unisex clothing
Women's clothing
Specialty clothing
Design and finishing
Headgear
Shoes
Dress accessories
Miscellaneous accessories
Personal adornment and articles
Personal adornment
Personal articles
Arts and architecture
Ancient architecture
Military architecture
Western architecture
International style skyscraper
Asian and pre-Columbian architecture
Elements of architecture
Housing
Fine arts
Graphic arts
Intaglio printing process
Performing arts
Music
Examples of instrumental groups
Traditional music instruments
Crafts
Communications
Languages of the world
Written communication
Photography
Digital non-reflex cameras
Telecommunications
Telecommunication satellites
Telecommunications by satellite
Radio
Microphones and accessories
Stereo sound system
Elements of a stereo sound system
Wireless communication
Telephony
Office automation
Computer equipment
Miscellaneous computer tools
Networking
Office
Transport and machinery
Road transport
Automobile road transport
Cycling road transport
Rail transport
Diesel-electric locomotive
Urban rail transport
Maritime transport
Examples of boats and ships
Air transport
Forces acting on an aircraft
Handling
Heavy machinery
Energy
Geothermal energy
Production of electricity from geothermal energy
Fossil energy
Hydroelectricity
Steps in the production of electricity
Nuclear energy
Production of the electricity from nuclear energy
Solar energy
Flat-plate solar collector
Production of electricity from solar energy
Wind energy
Wind turbines and electricity production
Science
Chemistry
Physics: mechanics
Physics: electricity and magnetism
Physics: optics
Trajectory of light waves
Measuring devices
Measurement of the temperature
Scientific symbols
International System of Units (SI)
Society
City
Economy and finance
Examples of currency abbreviations
Money and modes of payment
Justice
Education
Religion
Politics
Flags of international organisations
Weapons
Weapons of the age of the Romans
Thrusting and cutting weapons
War arsenal
Seventeenth-century firearms
Seventeenth-century cannon and mortar
Safety
Respiratory system protection
Health
Pharmaceutical forms of medication
Family
Sports and games
Sports facilities
Track and field
Ball sports
Racket sports
Gymnastics
Aquatic and nautical sports
Canoe-kayak: flatwater racing
Combat sports
Strength sports
Equestrian sports
Precision and accuracy sports
Cycling
Motor sports
Winter sports
Sports on wheels
Aerial sports
Mountain sports
Outdoor leisure
Games