下面哪些攻击属于服务攻击（）
I.邮件炸弹攻击
II.源路由攻击
III.地址欺骗攻击
IV.DOS攻击

A Road Accident It was raining (11) as I was walking up the hill towards the station at six o'clock on a Saturday morning. At this early hour there wasn't much (12) and there weren't many people in sight. Just as I was (13) the road near the top of the hill, a car came round the (14) . It was travelling very fast and the driver was (15) having difficulty in controlling it. Suddenly it swerved (16) , skidded on the wet road, hit a lamp -post and turned over. At once I ran to the car to (17) the driver, but he was unconscious and there was a lot of blood on his face. A young woman hurried into the station and phoned for an ambulance while I took care of the driver. (18) . A policeman arrived a few minutes later and asked me a lot of questions about the accident. (19) . On Monday morning I went to the hospital to inquire about the man. (20) . 点击查看答案

Complete the following sentences. Use NO MORE THAN THREE WORDS for each answer. The speaker identifies the following two differences between being a high school student and a university student: the academic expectations of tutors and lecturers are ______. students must take responsibility for their own learning.（） 点击查看答案