To maintain a monopoly, there must be barriers to entry. barriers to entry include of resources without close substitutes; of scale; legally required licenses, franchises, and certificates of convenience; patents; tariffs; and safety and quality regulations.
ownership; economies ( true or false )

Ownership,economies. This statement is true.

Explanation:

A monopoly is referred to as or known as the circumstance under which an organization and the commodity it is offering tends to dominate the sector or the market or the industry. Monopolies are usually considered to be an extreme outcome of the capitalism in free-market in the absence of any restraints or restriction.

the page presents four different kinds of threats that volcanoes pose and what to do before, during, and after an eruption.

answer; (c) communism and socialism;