All postgraduates have strong research ability, and anyone with strong research ability can enter the university to be a teacher. Some graduates from Fuzhou have become university teachers; some doctoral graduates from Fuzhou have also become University teacher; for some reason, the wives of all PhD graduates who came to Fuzhou did not move into Fuzhou. Based on this text, which of the following can't be judged? ['All postgraduates can enter the university as teachers.', 'Some university teachers have strong research skills.', "Some college teachers' wives do not move into Fuzhou.", 'Some wives of graduate students have not moved to Fuzhou.']