如图所示，在小车的一端高h的支架上固定着一个半径为R的1/4圆弧光滑导轨，一质量

材料一：穿棉布衣服还是化纤衣服？坐电梯还是爬楼梯？开车还是走路？在一部分中国人的眼里，这不再是随机的选择而是严肃的生活态度问题，他们追求的是“低碳”或“乐活”的生活方式，通过日常生活的每个细节改变来减少二氧化碳的排放，这就是所谓的“低碳”的生活方式。和“低碳”一样流行起来的概念还有“乐活”，这是英文LOHAS的译音，指健康、环保的生活方式。

（1）“低碳”和“乐活”的生活方式体现了什么发展理念？（1分）

（2）提倡“低碳”和“乐活”的生活方式有什么现实意义？（2分）（至少两点）

材料二： 2010年6月5日是第三十八个世界环境日。联合国环境规划署将今年的主题确定为“多样的物种·唯一的星球·共同的未来”，旨在保护生物多样性。

（3）导致大自然物种减少的原因是什么（2分）

材料三：中国环境保护部门也确定了2010年“6·5”世界环境日中国主题:“低碳减排·绿色生活”，号召公众从我做起，推进节能减排，践行绿色生活，为建设生态文明、构建环境友好型社会贡献力量。

（4）“低碳减排·绿色生活”表明中国政府坚持什么样的国策？（1分）

（5）“低碳减排·绿色生活”，我们中学生能做些什么？（3分）（至少三点）

斜井跟车工必须熟悉本岗位的（）等一般性能及使用方法

A、信号装置

B、制动装置

C、手动落闸装置

D、保护装置

某500kV变电所中有750MVA、500／220／35kV主变压器两台。35kV母线分列运行、最大三相短路容量为2000MVA，是不接地系统。拟在35kV侧安装几组并联电容器组。请按各小题假定条件回答下列问题。

如本变电所每台主变压器35kV母线上各接有100Mvar电容器组，请计算电容器组投入运行后母线电压升高值为（）。

A.13.13kV

B.7kV

C.3.5kV

D.1.75kV

The sudden, dramatic explosion in value of online social media sites like Facebook and Twitter is reminiscent of the rise, about 15 years ago, of the online businesses that created the "dotcom bubble. " The Internet was far less widely used than it is today. Still, visionaries saw the potential for the Internet we have today, so virtual companies sprung up and grew like weeds as investors threw money their way. Some, like Google and Amazon, developed an enduring online presence and lasting financial value. But far too many quickly lost value when it became apparent that their rapid growth wasn’t yielding revenue.

So, how much is Facebook’s network of users really worth The potential is clear—when so many people are gathered in one virtual place, offering so much personal information about themselves, they create an unprecedented platform for targeted advertising. Or they would, if they were on the network to shop. When eBay and Amazon suggest products to their customers, they’re talking to people who’ve already proven that they’re interested in buying similar products. People go on Facebook for a variety of reasons-to catch up with old friends, share pictures, make new acquaintances, and talk, sometimes endlessly, about themselves. Whether they’ll appreciate having their virtual conversations interrupted by advertising, targeted or not, remains unclear.

It’s also unclear whether Facebook will actually be able to share information about its users’ browsing habits with advertisers. Complaints about the ineffectiveness of Facebook’s privacy policies have arisen in multiple countries, part of a larger social concern about how private information gets used on line. In December, the Federal Trade Commission issued a proposed framework that, among other things, would permit Facebook users to block advertisers from accessing information about their online interests. If that framework is implemented and widely used by Facebook subscribers, it could seriously impair the site’s value as a potential platform for targeted marketing.

What is clear is that Goldman Sachs has a significant interest in Facebook’s financial value, at least for the short term. Goldman Sachs’ decision to invest heavily in Facebook has had some interesting impacts. For one thing, the investment has allowed Facebook an opportunity to postpone issuing an IPO. That means that, at least for the moment, Facebook doesn’t yet have to disclose its finances or publicly address investor complaints.

Goldman Sachs’ investment also puts the firm in an ideal position to handle Facebook’s IPO when it eventually is issued, perhaps sometime next year. That, of course, has the potential to generate substantial revenues for Goldman Sachs’ clients. Google’s 2004 IPO raised an initial $1.2 billion for the company. After all the propaganda, Facebook’s IPO can hardly be expected to raise less. However, there remains a significant question as to whether Facebook’s potential for generating income is more virtual than real. If it turns out that Facebook can’t live up to its potential for generating advertising revenue, venture capitalists who invest for the long term may get burned.

The dot-com bubble demonstrates that（）

A. Facebook will generate substantial profits for its investors

B. potential profits assigned to dotcom firms don’t always materialize

C. no dotcom companies can ripe any revenues from issuing their IPO

D. Facebook will certainly disappoint its investors in the long run

在VOR台上空左等待，向台航迹为0°，现飞机以航向300°向VOR台飞行，加入等待程序的方法是（）.

A.直接进入

B.偏置进入

C.平行进入