机车车辆在轨道上运行时产生以下那些力（）。A、横向水平力 B、垂直压力 C、惯性力

　　①随着计算机在现实生活中的广泛应用，与之相关的词汇不仅越来越多，也越来越为大众所熟悉。不久前，一位“菜鸟”问笔者：“听人说得给电脑打‘补丁’，这是怎么回事呀？”是呀，电脑又不是衣服。怎么和“补丁”扯上了？但此“补丁”非彼补丁，正如电脑病毒之于生物意义上的病毒，完全是两码事。

　　②计算机领域的补丁，是电脑程序，从某种意义上讲，也是程序的一个“怪胎”。简言之，作为程序的“补丁”的出现，主要基于原程序的漏洞，而原程序的漏洞又是人的思维的漏洞的必然反映，是遗憾，更是无奈。

　　③我们知道，程序设计是一项复杂的脑力劳动。简单的程序倒也罢了，复杂一些的程序，程序员要做的工作就非常庞杂了。至于像操作系统那样的“特大”程序，就不是一两个人的力量所能完成的了，而是需要集合集体的智慧。“人非圣贤，孰能无过？”何况是许多人共同完成的一项工作。于是，思维上的漏洞体现在程序设计中就成了程序的漏洞。程序有漏洞，计算机用户在使用过程中就会出问题。在当今互联网时代，程序上的漏洞又会给网络黑客以可乘之机。

　　④给电脑打“补丁”，其实就是安装补丁程序，借此改正原程序设计中的错误，堵住程序漏洞。电脑程序越复杂，漏洞往往越多，正如一部长篇巨著中出现的语法、文字和标点符号等方面的错误往往会远远多于一篇短文所出现的。所以，我们常常能看到微软公布的Windows操作系统的漏洞及相关的补丁程序”。

　　⑤遗憾的是，许多计算机用户并不了解补丁程序是怎么一回事，也有一些用户虽然对此有所了解，但由于懒惰或疏忽大意163874、也没能及时去打“补丁”，致使一些别有用心的网络破坏者，利用微软公布的漏洞兴风作浪。例如，2003年7月下旬，微软公布了其WindowS操作系统中广泛存在着RPC漏洞及补丁程序。结呆，仅二十多天之后，针对这一漏洞的病毒，就开始在互联网上传播开来。很快，全球就有二千多万台电脑被感染。所以有人说，微软的好心带来了恶果。不过，这也说明，对于微软将“漏洞”和“补丁”的“公之于众”，倒是那些黑容更为关注，而大多数计算机用户却不甚关心。

　　⑥计算机“补丁”，除了专门堵漏洞的，还有一些具有其他功能的“补丁”，如汉化补丁、游戏补丁、增强型补丁等等。

1．根据文章内容说说标题中“补丁”的含义。

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2．为什么要给电脑打“补丁”？ 

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3．电脑程序漏洞产生的原因是什么？

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4．本文主要运用了什么说明方法？请举例说明。

______________________________________________

5．读了本文，你有哪些收获？

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阅读理解。

     No matter what hairstyles youngsters wear, they will be looking good as they turn pages, thanks

to a new literacy (读写能力) project that inspires boys to read and rewards them with free haircuts.

George Cook ?, a sixth grader at Middle Township Middle School in Cape May Court House, is

just one of the 2010 Youth Leaders for Literacy Grant winners for his creative communitybased

project that offers reading inspiration.

     America's youngsters created some big ideas to get kids reading. This year, Youth Leaders for

Literacy is awarding 30 cash grants of $ 500 each to winners, totaling $ 15,000.

The National Education Association (NEA) joined forces with Youth Service America (YSA) to

develop Youth Leaders for Literacy to encourage community service through innovative (创新的)

youthdesigned programs that benefit others in their communities.  The national competition received

more than 200 entries (参赛作品)-an amount that continues to grow each year with the program's

popularity.

     "Educators and parents face a daily challenge of how to develop children's interest in reading,"

said NEA President Reg Weaver. "When youngsters are encouraged to brainstorm and design l

iteracy programs for their generation, it's another solution for the reading blues that really works."

     Developed in 2001, the youthled activities are started on NEA's Read Across America Day,

celebrated this year on Monday, March 3, and end during YSA's Global Youth Service Day, scheduled

for April 25-27, 2010. Attached is a list of the 30 grant winners being honored from across the country.

     "The Youth Leaders for Literacy Grant winners demonstrate global caring and decisions, showing

the world that young people can be leaders today, not in some distant tomorrow," said Steve Culbertson, president and CEO of YSA. "By combining the dynamics of leadership, service and learning, the Youth

Leaders for Literacy recipients build one of the most important skills-the ability to read."

1. Why did George Cook ? become the 2010 Youth Leaders for Literacy Grant winner?

A. Because he put forward an innovative project.

B. Because he looked good when turning pages.

C. Because he offered the youngsters free haircuts.

D. Because he helped Youth Leaders for Literacy before.

2. What can be inferred from the passage?

A. Winners will have their hair cut free.

B. It is not easy to develop children's interest in reading.

C. Youth Leaders for Literacy will choose over 30 winners this year.

D. 200 people enter Youth Leaders for Literacy competition each year.

3. The underlined phrase "the reading blues" in Paragraph 4 refers to ________.

A. youngsters' reading ability                          

B. people's feeling on reading

C. youngsters' unwillingness to read        

D. the colour of the readers' face

4. What would be the best title for the passage?

A. Youngsters Can Have Free Haircuts

B. The Ability to Read Is Very Important

C. How to Design New Reading Program for Youngsters

D. Youth Leaders for Literacy Pays Off

室间隔缺损伴有肺动脉高压时，不应出现的表现是（）

A.原有心脏杂音显著增强

B.右心室显著增大

C.肺动脉第2音显著亢进

D.X线胸片肺动脉段显著膨出

E.右心室压力显著升高

采购人、采购代理机构应妥善保存政府采购文件，保存期限为从采购结束之日起至少（）。

A．15年

B．10年

C．5年

D．3年

A typical application of this (71) is ADSL. It is emerging as the technology for home-and small-office Internet connectivity. It provides either 1.5 Mb/s～8 Mb/s from the network to the user and 64 kb/s～512 kb/s in the reverse direction depending on the distance, 12000 or 18000 feet. The different speed for each direction gives it the (72) label. ADSL is designed to take advantage of the fact that video-on demand, telecommuting, and Internet access traffic are inherently asymmetrical. The user (73) a brief message up to the network and receives a ton of data coming back, either a movie or a piece of data download. Under such a scenario, low-speed traffic to the network is just fine. ADSL .delivers high (74) where you need it and only uses a single copper pair. Through multiplexing, it also reserves (75) of the bandwidth for POTS.

A．sends

B．personates

C．receives

D．writes