Close to his undergraduate graduation, Li Ming has achieved excellent results in all his courses. According to the regulations of the University, if his course scores are excellent in the last semester, he can be exempted from the examination to study as a graduate student. Li Ming failed to get an excellent grade in one subject in the last semester, so he can't be exempted from the examination to study as a graduate student.
The above argument has loopholes because it has a mature understanding of the provisions stated in the title stem as: only if the course scores of all semesters are excellent, can they be exempted from the examination to study as graduate students is the most appropriate evaluation of the above argument.