Final answer:
A characteristic of pure monopoly is barriers to entry, which can be due to economies of scale, control of resources, or intellectual property laws, resulting in a single firm dominating the market.
Step-by-step explanation:
A characteristic of pure monopoly is the existence of barriers to entry, which prevent or discourage other firms from entering the market. These barriers can be a result of various factors including economies of scale that lead to a natural monopoly, control of a scarce physical resource, intellectual property laws such as patents, copyrights, trademarks, and trade secrets, legal restrictions on competition, or practices like predatory pricing that intimidate potential competitors. In the case of a natural monopoly, the quantity demanded is only sufficient for one firm to operate at the minimum of the long-run average cost curve, restricting the market to a single provider.