题目

如图所示，一轻质弹簧两端分别与竖直墙壁和物块连结,弹簧、地面水平。A、B是物块能保持静止的位置中离墙壁最近和最远的点，A、B两点离墙壁的距离分别是x1、x2。物块与 地面的最大静摩擦力为f。则弹簧的劲度系数为 A.       B. C.       D.       答案：CThe task of being accepted by a university begins early for some students.Long before1.(graduate) from high school,these students take special courses to prepare for advanced study.They may also take one or more examinations to test how well prepared they are for the university.In the final year of high school,they complete 2.(apply) and send them to the universities3.interest them most.Some high school students may be required to have4.interview with people from the university.Neatly5.(dress) and a little bit frightened,they are determined 6.(show) that they have a good attitude and the ability to succeed.If the new students7.(accept),many universities will offer an instruction programme for them to get to know the procedures for students advising,university rules,the use of the library and all the other major services of the university.Beginning a new life in a new place can be very8.(confuse).The more knowledge students have about the school,the9.(easy) it will be for them to adapt to the new environment.However,10.takes time to get used to college life.