【正确答案】 C

【答案解析】[听力原文]
   During the stammer session there will be a revised schedule of services for the university community. Specific changes for intercampus bus services, summer hours for the cafeteria and recreational and athletic facilities will be posted on the bulletin board outside the cafeteria. Weekly movie and concert schedules which are in the process of being arranged will be posted each Wednesday outside the cafeteria.
   Intercampus buses will leave the main hall every hour on the haft hour and make all of the regular stops on their route around campus. The cafeteria will serve breakfast, lunch, and early dinner from 7 a.m. to 7 p.m. during the week and from noon to 7 p.m. on weekends. The library, will maintain regular hours during the week, but shorter hours on Saturdays and Sundays. The weekend hours are from noon to 7 p.m.
   All students who want to use the library borrowing services and recreational athletic, and entertainment facilities must have a valid summer identification card. This announcement will also appear in the next issue of the student newspaper.
   Which of the following is the main purpose of this announcement?
四个选项均以To开头表示目的。开头句就交待了主题，其中的核心词是revised schedule，C中的change是文中revise的同义词，答案为C。