下列楼梯间防烟系统形式设置正确的是（  ）。

下列新生的细胞属于机化时出现的特征细胞的是

下列腧穴中，不属于督脉的是

关于水泥混凝土面层接缝设置的说法，正确的是（   ）。

一般认为，使用成瘾性物质后产生“快感”是由于

《绿野仙踪》是儿童文学史上的一部经典著作。其作者是 ( )。

青年女，月经第5d，经血刮片同时见分泌期子宫内膜、出血坏死性组织和增生期子宫内膜。考虑的原因是（     ）。

根据《证券法》，向不特定对象发行证券聘请承销团承销的，承销团应当由主承销和参与承销的（  ）组成。

Passage2

     Old stereotypes diehard. Picture a video-game player and you will likely imagine a teenage boy, byhimself, compulsively hammering away at a game involving rayguns and aliensthat splatter when blasted. Ten years ago that might have borne some relationto reality. But today a gamer is as likely to be a middle-aged commuterplaying  "Angry Birds" on hersmartphone. In America, the biggest market, the average game-player is 37 yearsold. Two-fifths are female.

     Over the past tenyears the video-game industry has grown from a small business to a huge, mainstreamone. With global sales of $56 billion in 2010, it is more than twice the sizeof the recorded-music industry. Despite the downturn, it is growing by almost9% a year.

    Is this success dueto luck or skill? The answer matters, because the rest of the entertainmentindustry has tended to treat gaming as being a lucky beneficiary of broadertechnological changes. Video gaming, unlike music, film or television, had theluck to be born digital. In fact, there is plenty  for old media to learn.

    Video games have certainly been swept along bytwo forces: demography and technology. The first gaming generation-the childrenof the 1970s and early 1980s-is now over 30. Many still love gaming, and canafford to spend far more on it now. Meanwhile rapid improvements in computingpower have allowed game designers to offer experiences that are now often morecinematic than the cinema.

     But even grantedthis good fortune, the game-makers have been clever. They have reached out tonew customers with new methods. They have branched out into education,corporate training and even warfare, and have embraced digital downloads andmobile devices with enthusiasm. Though big-budget games are still popular, muchof the growth now comes from  "casual" games that are simple, cheap and playable in shortbursts on mobile phones or in web browsers.

     The industry hasexcelled in a particular area-pricing. In an era when people are disinclined topay for content on the web, games publishers were quick to develop"freemium" models, where you rely on non-paying customers to build anaudience and then extract cash only from a fanatical few.

Asgaming comes to be seen as just another medium, its tech-savvy approachcould provide awelcome shot in the arm for existing media groups.

One special factor of the success of video games is that_____.

由于完全竞争行业的短期供给曲线是该行业中所有厂商短期供给曲线的水平相加，那么该行业的长期供给曲线也是该行业中所有厂商长期供给曲线的水平相加。（　　）

患儿，1.5岁 。未接种过麻疹疫苗，近4天来出现发热、流涕、打喷嚏、畏光，昨日体温稍降，今日又发热 。查体见耳后发际部出现红色斑丘疹，疹间皮肤正常 。血白细胞4.5×10⁹/L 。最可能的诊断是