ANormally a student must attend a certain number of courses in order to graduate, and each course which he attends gives him a credit which he may count towards a degree. In many American universities the total work for a degree consists of thirty-six courses each lasting for one semester(学期). A typical course consists of three classes per week for fifteen weeks; while attending a university a student will probably attend four or five courses during each semester. Normally a student would expect to take four years attending two semesters each year. It is possible to spread the period of work for the degree over a longer period. It is also possible for a student to move between one university and another during his degree course, though this is not in fact done as a regular practice.For every course that he follows, a student is given a grade, which is recorded and the record is available for the student to show to potential employers. All this imposes (增加) a constant pressure and stress of work, but in spite of this, some students still find time for great activity in student affairs. Elections to positions in student organizations arouse much enthusiasm. The effective work of maintaining discipline is usually performed by students who advise the academic authorities. Any student who is thought to have broken the rules, for example, by cheating, has to appear before a student court. With the enormous numbers of students, the operation of the system does involve a certain amount of activity. A student who has held one of these positions of authority is much respected and it will be of benefit to him later in his career.Normally a student would at least attend classes each week.A.36B.12C.20D.15According to the first paragraph an American student is allowed .A.to live in a different universityB.to change permanently his or her universityC.to live at home and drive to classesD.to take a particular course in a different universityAmerican university students are usually under pressure of work because .A.their academic performance will affect their future careersB.they are heavily involved in student affairsC.they have to obey university rulesD.they want to run for positions of authoritySome students are enthusiastic for positions in student organizations probably because .A.they hate the constant pressure and stress of their studyB.they will then be able to stay longer in the universityC.such positions help them get better jobsD.such positions are usually well paidThe student organizations seem to be effective in .A.dealing with the academic affairs of the universityB.ensuring that the students observe university regulationsC.evaluating students' performance by bringing them before a courtD.keeping up the students' enthusiasm for social activities