A、September. B、Summer semester only. C、At the beginning of any quarter. D、At the beginning of the academic year. C

Although most universities in the United States are on a semester system, which offers classes in the fall and spring, some schools observe a quarter system comprised of fall, winter, spring, and summer quarters. The academic year, September to June, is divided into three quarters of eleven weeks each beginning in September, January, and March; the summer quarter, June to August, is composed of shorter sessions of varying length.
   There are several advantages and disadvantages to the quarter system. On the plus side, students who wish to complete their degrees in less than the customary four years may take advantage of the opportunity to study year round by enrolling in all four quarters. In addition, although most students begin their programs in the fall quarter, they may enter at the beginning of any of the other quarters. Finally, since the physical facilities are kept in operation year round, the resources are used efficiently to serve the greatest number of students. But there are several disadvantages as well. Many faculties complain that the eleven-week term is simply not long enough for them to cover the material required by most college courses. Students also find it difficult to complete the assignments in such a short period of time.
   In order to combine the advantages of the quarter system with those of the semester system, some colleges and universities have instituted a three-term trimester system. In fourteen weeks, faculty and students have more time to cover material and finish course requirements, but the additional term provides more options for admission during the year and accelerates the degree programs.
Questions 22 to 25 are based on the passage you have just heard.
22. Which of the following would be the best title for this passage?
23. How many terms are there in a quarter system?
24. When may students begin studying in a school that uses a quarter system?
25. Which of the following characteristics does not apply to trimesters?