单选题从数字0，1，2，3，4，5中选出5个数字，组成无重复数字的5位数，其中能被5整除的个数为______．

单选题______．A．4B．5C．D．E．

单选题设ζ1=(1，0，2)T，ζ2=(0，1，-1)T都是齐次线性方程组AX=0的解，则A=______。A．B．C．D．

单选题______．A．B．C．D．

单选题王刚和赵宏一起工作，1h可打出9000字的文件，已知王刚打字速度是赵宏打字速度的一半，那么赵宏单独工作1h打( )字． (A) 3000 (B) 4000 (C) 6000 (D) 8000

单选题已知两个等差数列{an}和{bn}的前n项和分别为Sn和Tn，且，则A．B．C．D．E．

单选题“龟兔赛跑”讲述了这样的故事：领先的兔子看着慢慢爬行的乌龟，骄傲起来，睡了一觉，当它醒来时，发现乌龟快到终点了，于是急忙追赶，但为时已晚，乌龟还是先到达了终点……用S1、S2分别表示乌龟和兔子所行的路程，t为时间，则下图与故事情节相吻合的是______A．B．C．D．E．以上答案均不正确

单选题袋中装有 6 个球，其中红白黑各 2 个，现随机从中摸出 3 个球，则恰好是三个不同颜色的球的概率为（ ） 。

单选题已知长方形的长为8，将长方形的一条对角线折起压平如图2—28所示，则阴影三角形的面积等于{{U}}{{/U}}．A.8B.10C.12D.14

单选题已知I=0，1，2，3，4，5，A=1，3，5，B=0，2，4，则CIA∩B=______。A．B．AC．BD．I

单选题{an}是等差数列，已知m≠k，Sm=Sk=b，则Sm+k={{U}} {{/U}}。 A.0 B.b C.2b D.4b

单选题某公司财务处有甲、乙、丙、丁、戊五名职员，现进行换岗，随机抽取岗位，可与原岗位相同，则有且只有一人与原来的职位一样的概率为______．A．B．C．D．E．

单选题 Old people are always saying that the young are not what they were. The same comment is made from generation to generation and it is always true. It has never been truer than it is today. The young are better educated. They have a lot more money to spend and enjoy more freedom. They grow up more quickly and are not so dependent on their parents. They think more for themselves and do not blindly accept the ideals of their elders. Events which the older generation remembers vividly are nothing more than past history. This is as it should be. Every new generation is different from the one that preceded it. Today the difference is very marked indeed. The old always assume that they know best for the simple reason that they have been around a bit longer. They don't like to feel that their values are being questioned or threatened. And this is precisely what the young are doing. They are questioning the assumptions of their elders and disturbing their complacency. They take leave to doubt that the older generation has created the best of all possible worlds. What they reject more than anything is conformity. office hours, for instance, are nothing more than enforced slavery. Wouldn't people work best if they were given complete freedom and responsibility? And what about clothing? Who said that all the men in the world should wear drab gray suits and convict haircuts? If we turn our minds to more serious matters, who said that human differences can best be solved through conventional politics or by violent means? Why have the older generation so often used violence to solve their problems? Why are they so unhappy and guilt-ridden in their personal lives, so obsessed with mean ambitions and the desire to amass more and more material possessions? Can: anything be right with the rat-race? Haven't the old lost touch with all that is important in life? These are not questions the older generation can shrug off lightly. Their record over the past forty years or so hash't been exactly spotless. Traditionally, the young have turned to their elders for guidance. Today, the situation might he reversed, The old--if they are prepared to admit it--could earn a thing or two from their children. one of the biggest lessons they could learn is that enjoyment is not "sinful". Enjoyment is a principle one could apply to all aspects of life. It is surely not wrong to enjoy your work and enjoy your leisure; to shed restricting inhibitions, It is surely not wrong to live in the present rather than in the past or future. This emphasis on the present is only to be expected because the young have grown up under the shadow of the bomb: the continual threat of complete annihilation. This is their glorious heritage. Can we be surprised that they should so often question the sanity of the generation that bequeathed it?