在山地行走时，错误的做法是（）。A.如果不是高山，沿着山脊潜行， B.穿越山岭时，尽

下列说法：①同位角相等；②对顶角相等；③等角的补角相等；④同旁内角相等，两直线平行．其中正确的个数是（　　）

A．1个

B．2个

C．3个

D．4个

6个数分别表示为a、b、c、d、e、f；其中a、b、c、d的平均值为10；b，c，d，e，f的平均值为14．若f是a的两倍，那么，a和e的平均值等于______．

某单位举行一次大型会议，与会者中发生了不明原因的上呼吸道疾病。为确定此病的罹患率，对居住在6个旅馆的代表进行调查以了解发病情况。由于调查全部代表难以实施，故随机抽样提供了较全面的资料。因为（）

A、它将识别出全部病例

B、它将会避免因选择住宿代表时引入的各种偏倚

C、它将会消除抽样误差

D、它使每个代表有同样的机会被抽中

E、随机抽样的数据较调查全部住宿代表的数据易于处理

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 text is written to answer the question（）

A. Will the social media be the next dotcom bubble

B. Does Goldman Sachs really want to invest in Facebook

C. When will it be the right time for Facebook to issue its IPO

D. What lessons can we learn from the ups and downs of social media

下列关于发掘人的创造潜能的定律理解不正确的是（）

A、拴桩定律使人才无后顾之忧，使人才有用武之地

B、公正定律为具有创新精神和创新能力的人才提供一个公共的机会和舞台、政策和规则、管理和服务

C、鲇鱼定律人才需要有一个压力，必须处在激烈的竞争环境当中才会出成绩，压力越大越好

D、人本定律为具有创新能力的人才提供一个人本的环境，更有利于拴心留人