Please read attached chapter “Market Structures” in reference.rar. Give solutions for 4 questions below.1. Explain the following concepts briefly by searching the definitions on the web : Economic Profits, Economies of scope, vertical integration, buyer’s imperfect information, cartels.2. Based on the chapter, why does not Perfect Competition usually happen? Please summarize your arguments, not more than 100 words. 3. Why are cartels illegal in USA? Based on chapter, what are the problems to maintain cartels?4. Based on the chapter, please explain pricing strategies of oligopolies. Please summarize, not more than 100 words.