(本题满分12分) 在等差数列{an}中，若a2＋a3＋a4＋a5＝34，且a2

从利率角度分析，（）形成了利率下调的稳定预期。

A.通货膨胀

B.通货膨胀率

C.通货紧缩

D.通货紧缩率

补写出下列名句名篇中的空缺部分。（任选3题，多选只按前3题计分。答对一空给分）（6分）

（1）          ，             。哀吾生之须臾，羡长江之无穷。（苏轼《赤壁赋》）

（2）飞来山上千寻塔，闻说鸡鸣见日升。         ，        。（王安石《登飞来峰》）

（3）可堪回首，        ，        。（辛弃疾《永遇乐·京口北固亭怀古》）

（4）我闻琵琶已叹息，又闻此语重唧唧。          ，         。（白居易《琵琶行》）

电动开门器的手动控制按钮应设置在防火门内侧墙面上，距门不宜超过（）m，底边距地面高度宜为O.9m-1.3m。

A、0.5

B、0.8

C、1

D、1.2

保护社会和公众的生命与财产安全是安全防范从业人员职业道德的核心内容

Internet advertising is booming. The industry has gone from $ 9.6 billion in revenue in 2001 to $ 27 billion this year, according to Piper Jaffray, an investment bank. And it is still early days. The internet accounts for only 5% of total spending on advertising, but that figure is expected to reach at least 20% in the next few years. The single largest category within this flourishing industry, accounting for nearly half of all spending, is "pay-per-click" advertising, which is used by firms both large and small to promote their wares.

The benefits of the pay-per-click approach over traditional advertising (television, radio, print and billboards are obvious. Since advertisers pay only to reach the small subset who actually respond to an advertisement, the quality of the leads generated is very high, and advertisers are prepared to pay accordingly. The price: per click varies from $ 0.10 to as much as $ 30, depending on the keyword, though the average is around $ 0.50. Google made most of its $ 6.1 billion in revenue last year from pay-per-click advertising.

But as pay-per-click advertising has grown into a huge industry, concern has mounted over so-called "click fraud"--bogus clicks that do not come from genuinely interested customers. It takes two main forms. If you click repeatedly on the advertisements on your own website, or get other people or machines to do so on your behalf, you can generate a stream of bogus commissions. Click fraud can also be used by one company against another: clicking on a rival firm’s advertisements can saddle it with a huge bill. Bogus clicks are thought to account for around 10% of all click traffic, though nobody knows for sure.

A few months ago Mr. Gross pioneered an alternative to the pay-per-click model. In February, Snap, a search engine backed by Mr. Gross, launched "pay-per-action" (PPA), a new model in which advertisers pay only if a click on an ad is followed by an action such as a purchase or a download.

Might this put an end to click fraud Don’t bet on it, says Mike Zeman at Starcom, an advertising agency. Payper-action will be a niche, he predicts, since converting a click into an action depends on a variety of factors such as the ease of use of the advertiser’s website. Google and its peers will be reluctant to be so dependent on factors outside their control. But Mr. Tobaccowala thinks pay-per-action could become a real alternative to pay-per-click. As bigger companies spend more on internet advertising; they will demand more accountability and a wider range of options, he says. At the very least, that means clamping down on click fraud; but it also presents an opportunity for entrepreneurs to invent new models that are less vulnerable to abuse.

Which of the following is true of the text（）

A. Although the risk exists, the internet advertising still can earn a lot of profit

B. The PPA will substitute the original click advertising model

C. All operators start to satisfy the advertisers by using PPA

D. The entrepreneurs are pleasantly surprised by the temporary solution