Final answer:
Government regulations limit the entry of new firms in industries such as computer operating software, commercial aircraft, and basic steel.
Step-by-step explanation:
The answer to your question is government regulations.
Government regulations often control and limit competition in certain key industries like computer operating software, commercial aircraft, and basic steel. These regulations can include requiring businesses to obtain permits and pay fees, restricting the types and quality of products they can sell, and imposing zoning laws that limit where companies can conduct business.
For example, in the case of computer operating software, governments may impose regulations that require new software companies to meet certain technical standards or obtain specific licenses, making it difficult for new firms to enter the market and compete with established companies.