A Chinese graduate student at Boston University was the third victim of Monday's bombing at the finish line of the Boston Marathon, the university announced Tuesday. University officials said that the student, whom it did not identify pending approval from his family, was among a trio of B.U. students and friends who watched the end of the marathon from near the finish line. Another graduate student was injured and remains hospitalized, the university said. Boston-area colleges continued to report that some of their students were injured, including seven from Emerson College.