As the spring term starts, a new round of battle for seats in study rooms is being staged on China's campuses. Candidates for the 2016 Postgraduate Entrance Exam use chairs and books, some of which are pasted with threatening words, to reserve a desk and seat at a study room of a university in Henan province, despite the regulation prohibiting it. The battle for seats is so fierce that even space on the ground in a study room is marked off with paper slips. The 2016 Postgraduate Entrance Exam is scheduled to be held at the end of the year.

According to story, candidates are using tools to occupy seats EXCEPT for?

A. slogans with threatening words

B. books

C. paper slips

（中國日報網英語點津 劉明 編輯）