Two groups of students, one of them participated in the ancient Chinese training class, the other group did not participate. In the language test, the students who have participated in the ancient Chinese training class have a much higher average score than those who have not participated. To improve their grades in the language test, they must be allowed to participate in the ancient language training class. Which of the following are the assumptions since the above argument:. ['Many students participated in the ancient writing training class.', "Students' parents should teach students something.", 'The improvement of Chinese performance is not necessarily related to the participation in ancient Chinese training classes.', 'Only by participating in ancient Chinese training can improve language performance.']