A、For about 7 days. B、For about 10 days. C、For about 16 days. D、Only for weekends. B短文中提到，寒假期间，所有的宿舍楼中只有Butler Hall开放，其他宿舍楼在2月7日

Hello, everyone! Thank yOu for coming to this meeting.(15)Since all of you are those who will be remaining on campus to finish the research project during the winter break, now I want you to fill out the forms giving the dates you will be on campus. First of all, I want to let you know the work hours of different departments. To reduce heating costs, Butler Hall will be the only dormitory open.(16)All the others will be closed at 5:00 p.m. on Friday, Feb, 7 and won’t be reopened until 6:00 p.m. on Feb, 16. Once we have your completed forms, we’ll find you a room in Butler Hall. Please have all that you will need moved there by the 7th. Most college facilities, including the college store and the dining hall, will be closed during the vacation. The library and the computer center will be open, but on a reduced schedule.(17)Only the post office and the college office will keep their regular hours. Since I imagine most of you are staying here to finish the project, let me wish you good luck with your work. Now if you have any special problems, please don’t hesitate to ask me. Thank you!
15. Why will the students remain on campus during the vacation?
16. How long will most of the dormitories be closed?
17. What will remain open as usual?