Peer refers to the peers who are close to themselves in terms of age, status, interests, etc. Peer pressure refers to the psychological pressure caused by the achievements of peers. According to the above definition, Which of the following cases belong to peer pressure. ['Xiaoming saw a cheat sheet from a student in front of him during the exam, and wanted to report it to the teacher, and he was worried about being duplicated by the same journal, so he pretended not to see it.', 'Zhang Yuan has several university classmates working with him in the same hospital, and they have all been promoted to deputy senior titles, but they are still attending physicians and are very anxious.', "Film and television star Wu, who has been playing for many years, can't help but sigh that the days when he was in the film industry are gone.", 'Wang Li emigrated to another country twenty years ago and now sees the domestic economic situation is very good. Many acquaintances of that year have already flown to Huang Tengda and are envious.']