阅读理解。 These days the subject of security (安全) on campus is talked about quite often. Some students' mobile phones are stolen, some students fight with and hurt one another, and others are knocked down by the fast running bikes or cars. These problems arc common on campus. I think there are three causes for these. Firstly, some students do not take good care of their properties. They are still young and not careful enough. Secondly, some students want to do everything well. They want to be the winners in exams, and they also want to be the winners in fightings. And thirdly, the campus guards (保安) do not carry on their duties well. They don' t regulate the traffic in the busy hour. In order to have a secure campus, all the students should be very careful about their properties. They should also mind their behaviors (举止) and act politely. The campus guards are supposed to be devoted (致力于) to the security on campus, and it is their duty to safeguard (维护) a secure campus to help provide a good environment for the students. 1. According to the passage, some students' _______ are stolen. A. books B. clocks C. knives D. mobile phones 2. The passage tells us there are _______ causes for the problems. A. 2 B. 3 C. 4 D. 5 3. Some students want to be the _______ in exams and fightings. A. players B. singers C. winners D. teachers 4. The underlined word in Paragraph 2 'regulate' means '_______'. A. 关心 B. 维持 C. 赞同 D. 调节 5. This passage is mainly about _______. A. how to make the campus safe B. how to protect the students C. security rules on campus D. the importance of security campus