当屋架杆件在风吸力作用下由拉杆变为压杆时，其允许长细比为( )。A．100B．15

读“我国沿北纬32°纬线地形剖面图”，完成下列各题。

（1）在剖面图上标出我国三级阶梯的范围。

（2）写出图中数字代表的地理事物名称。

    ①_________；②_________；③_________；④_________；⑤_________。

（3）由图可知我国的地势具有什么特点？对气候和河流的影响是什么？

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阅读理解。

     Just 25 years ago, the top three career hopes for young people in Britain were teacher, banker and

doctor. Now, they want to be sports star, pop star and actor, according to survey by the Guardian

newspaper.

     Rachel, a character in the popular TV show Glee, may be said to speak for British teenagers.

"Nowadays being nobody is worse than being poor." He said.

     Emma Brockes, a reporter with the Guardian, believes it is "the bad influence of celebrity(名人)

culture" that is to blame. "When children wanted to be doctor, it wasn't because they were really more

interested in the functions of human organs than they are now; you go where the respect is." She wrote.

     It could explain why there has been such an increase in levels of anxiety and depression. Dr Carlo

Stranger, of Tel Aviv University, studied the sense of self for his new book The Fear of Insignificance:

Searching for Meaning in the 21st Century. He told the Daily Mail that young people now are "affected

by the close connection to the global entertainment network, which has turned ranking and rating people

according to wealth and celebrity into an obsession(痴迷)."

     "As humans, we naturally measure ourselves to those around us, but now we live in a global village.

We are comparing ourselves with the most 'important' people in the world and finding ourselves wanting," he said. Today, even high achievers constantly fear that they are insignificant when they compare

themselves to success stories in the media.

      The way out? Simply stop measuring your achievement through a fantasy of wealth and celebrity.

Dr Strenger said that it is a process called "active self-acceptance through a constant search for

self-knowledge through life."

     "The fear of insignificance can only be overcome through strong individual and cultural identity over

and above measurable achievement," he said.

1. Nowadays, young people in Britain want to         .      

A．choose jobs based on interests

B．become famous        

C．be teacher, banker and doctor            

D．earn more money

2. According to Emma Brockes, what causes the increasing level of anxiety?

A．Choices of future careers.  

B．Access to the global network.

C．Bad influences of celebrities.

D．Endless comparison with others.

3. Which of the following is true of Dr Carlo Strenger?

A．He is a newspaper reporter

B．He is the spokesman of teenagers.

C．He tells success stories on TV.

D．He is against ranking people with wealth.

4. Dr Carlo Strenger suggests that young people should         .

A．seek active self-acceptance

B．stick to their own dreams

C．make great achievements

D．search for the secret of wealth

5. The text is mainly written to         .

A．talk about job choices

B．analyse a social phenomenon

C．encourage celebrity culture

D．introduce three famous people

根据《水工建筑物地下开挖工程施工技术规范》（DL/T5099-1999），竖井单向自下面上开挖，距贯通面（）m时，应自上而下贯通。

A.3

B.5

C.8

D.10

绝对压力、表压力及大气压力三者之间的关系为（）。

A.P表=P绝+P大气；

B.P绝=P表+P大气；

C.P大气=P表+P绝；

D.P表=P大气一P绝

如图所示，在一根粗糙的水平直杆上套有两个质量均为m的铁环，两铁环上系着两根等长细线，共同拴住质量为M的小球，两铁环与小球都处于静止状态．现想办法使得两铁环间距离增大稍许而同时仍能保持系统平衡，则水平直杆对铁环的支持力F_N和摩擦力F_f的变化是（）

A.F_N不变

B.F_N增大

C.F_f增大

D.F_f不变