Shared leadership refers to an informal leadership team process model that is independent of the organization's formal leadership role or hierarchical structure and is actively participated by internal members of the organization. The sharing of behaviors or roles among members, such as decision-making, sharing of results, shared responsibilities, etc. , also emphasizes the mutual influence and cooperation between members, which is a level of influence distributed among members. Based on the above definitions, Which of the following are shared leaders:. ['In a new semester, the headteacher of a class initiates an activity in which the classmates take turns to be the monitor.', 'In order to improve service quality and efficiency, a department will deal with daily emergencies and emergency matters from the original several departments, and change it to a person in charge to the end.', "In the project design process of the company's project team, Xiao Wang took the initiative to undertake the task of technical research.", 'A R & D department implements democratic centralism in order to improve R & D efficiency and give full play to the enthusiasm of employees. Employees jointly exercise power, share responsibility and share benefits.']