Final answer:
The main characteristic of a unitary government, as seen in Chile, Peru, and Venezuela, is that it is governed as one single unit with a centralized legislature holding most of the power.
Step-by-step explanation:
Chile, Peru, and Venezuela are each considered unitary governments. A main characteristic of a unitary government is that it is governed as one single unit, with one constitutionally created legislature. This means that the central government holds the majority of the power, and while there may be local and regional governments, these are under the direct control of the central government, which has the ultimate authority. Unitary governments are contrasted with federal systems where power is divided between a central authority and its constituent parts, and with confederal systems where power is held more loosely by a coalition of independent states. Countries like the United Kingdom, France, and Japan have also followed this model, although some have decentralized powers through a process of devolution.