The definition of a trial is  a hearing in a court case, a test or a hardship. An example of trial is the court case of an accused robber. An example of trial is the use of a small size bottle of shampoo to sample the product.
An example of a market that meets all four conditions for perfect competition is: wheat. A market structure with many sellers and many buyers is: perfect competition. Offering products of different tastes and shapes is an example of: nonprice competition. An example of a barrier to entry is: high start-up costs. Compared to a market with perfect competition, a monopoly often has: higher prices and fewer goods. In many industries, deregulation has resulted in: lower prices for consumers. A market that is an oligopoly has: a few firms dominating the market.
Monopolies are unique relative to other market structures, as it only contains one firm, and thus a monopoly firm has far more power to set prices than firms in other market structures. Because of this lack of competition, monopoly firms will make an economic profit. 2  This would normally cause other firms to enter the market. 3  For this market to remain a monopolistic one, there must be some barrier to entry.