Specific language impairment (SLI) is diagnosed when a child's language does not develop normally and the difficulties cannot be accounted for by generally slow development, physical abnormality of the speech apparatus, autism spectrum disorder, acquired brain damage or hearing loss.
Perfect competition. A perfectly competitive market is a hypothetical market where competition is at its greatest possible level. Neo-classical economists argued that perfect competition would produce the best possible outcomes for consumers, and society.
There is some control over price in a narrow range, whereas the purely competitive firm has none. There is relatively easy entry; in pure competition, entry is completely without barriers. In monopolistic competition, there is much nonprice competition, such as advertising, trademarks, and brand names.