在系统维护中，由于上级部分的要求或用户为了操作方便而提出对程序中某些输入、输入格式与

水平方向做简谐运动的弹簧振子,其质量为m,最大速率为v,则下列说法中正确的是（    ）

A．振动系统的最大弹性势能为mv²

B．当振子的速率减为时，此振动系统的弹性势能为

C．从某时刻起，在半个周期内，弹力做的功可能不为零

D．从某时刻起，在半个周期内，弹力做的功一定为mv²

根据短文内容，从下框的A---F选项中选出能概括每一段主题的最佳选项。选项中有一项为多余项。

Bill，Emy，Ben，Brigitte和Susan五个人想购买杂志。阅读下面六本杂志(A、B、C、D、E和F ) 的介绍，选出符合各人需要的最佳选项。选项中有一项是多余选项。

注意： 该题要求做在答题卡上。选择E，则涂黑A+B, 选择F，则涂黑A+C

小题1:Bill travels a lot when he was younger．Now that he has stopped his work，he enjoys reading about foreign people，places and customs even if he has already visited that part of the world．

小题2: 

Emy is a university student studying Italian and Politics．She doesn’t have much time to read anything very detailed but she is looking for something with plenty of news and information．

小题3:Ben serves as an assistant to the general manager of an American company in Los Angeles．He is very interested in management and the use of high technology．

小题4:

Up till now Brigitte has never traveled far so this year she has decided to go abroad for the first time．The travel agent suggests that she should read about various countries first before choosing her holiday．

小题5:Susan likes shopping．She is interested in buying clothes and she needs to be offered advice on clothes．

A．Discover

News magazine of science devoted to the wonders and stories of modem science，written for the educated general reader．Published by Disney Magazine Publishing CO．，Discover tells many of the same stories professionals read in Scientific American．A truly delightful family science magazine，each issue brings to light new and newsworthy topics to make dinnertime and water-cooler conversations interesting．

B．World Travel

This weekly magazine can bring the world to your home．Have you ever wondered what the Chinese eat for breakfast? Did you know that the Sahara Desert is getting bigger every year? This fascinating magazine，full of color photographs，is your window to the world．

C．Self

Published by Conde Nast Publications Inc．，Self is a handbook devoted to women’s overall physical and mental health．Every issue contains usable articles such as “Style Lab”．in which wearable clothes are mixed and matched on non—models and the “Eat—Right Road Map”．with tips on how to eat properly．

D．Foreign Parts The weekly magazine tells what you need to know if you’re thinking of traveling．Helpful advice on what to pack and what to buy once you’re there．Lots of color photos to help you choose the best hotel, the cheapest flights and a special guide to different climates each week．

E．Wired

This magazine is designed for leaders in the field of information engineering including top managers and professionals in the computer，business，design and education industries．Published by Conde Nast Publications Inc，Wired often carries articles on how technology changes people’s lives．

F．Europe News

The weekly magazine keeps you in touch with what’s happening．Filled with facts and figures about almost everything you can think of, plus articles by our regular writers on the week’s most interesting news stories．Special back page sums up the news for the busy readers．

由于无形资产转让后加剧了市场竞争，在该无形资产的寿命期间，转让无形资产的机会成本通常表现为( )。

A．销售收入的增加折现值

B．销售费用的减少折现值

C．销售收入减少和费用增加的折现值

D．无形资产转出的净减收益与无形资产再开发净增费用

如图所示，质量m=20kg的物体，在斜向上方拉力F作用下，沿水平面向右匀速运动，物体与水平面间摩擦系数μ=0.1，求拉力F的大小（sin37°=0.6，cos37°=0.8，g=10m/s²）

生产经营单位使用国家明令淘汰、禁止使用的危及生产安全的工艺、设备的，责令限期改正；逾期未改正的，责令停产停业整顿，并可以并处( )罚款。

A．10万元以下

B．2万元以下

C．2万元以上

D．5万元以下