a zoo – a large place where many types
of wild animals are kept, usually in cages, so that people can see themA circus – group, people, animals, from place to place, people, movements, tricks
A circus – a group of people, and usually animals, that travels from place to place and entertains people by performing skilful or funny movements and tricks
A cage – structure, bares, wires, birds, animals
A cage – a structure of bares and wires in which birds or other animals are confined