Role ambiguity refers to the uncertainty of the job role positioning experienced by individuals, including the uncertainty of job responsibilities, uncertainty of work goals, etc. , so it often causes confusion in work processes and underground work efficiency. According to the above definition, which of the following is characters that are vague? ["Doctor Zhang has multiple positions, is the director of a hospital's orthopedics department, and also serves as the vice president of the hospital, a member of the regional medical society, etc.", "Su Li has just been promoted to deputy director of the customer service department. She doesn't know if she should handle it by herself. If she handles it, she will not exceed her current authority. She also doesn't know who to ask. She usually doesn't deal with these matters.", 'Xiao Chengang was an elementary school teacher and wanted to be friends with students. Although she has a close relationship with students now, she found that the students were not afraid of her, disobedient, or even handed in homework.', 'Xiao Zhang just joined the work and was full of enthusiasm. He wanted to give full play to his professional expertise in the job, but he had to do some work that has nothing to do with his specialty, so he felt that the psychological gap was very large.']