为满足北京奥运会期间各国运动员对蔬菜种类与营养的不同需求，中目农艺师引进了多种新品种

下列几种物理现象的解释中，正确的是(　　)

A．砸钉子时不用橡皮锤，只是因为橡皮锤太轻

B．跳高时在沙坑里填沙，是为了减小冲力

C．在推车时推不动是因为推力的冲量为零

D．动量相同的两个物体受到相同的制动力的作用，两个物体将同时停下来

如果点P（x，y）的坐标满足x+y=xy，那么称点P为和谐点．请写出一个和谐点的坐标：______．

2009年5月23日，小王作为前去参观第八届青岛国际车展的2000多名观众之一，有幸拿到了半岛都市报和市文明办联合发放的“爱心拒酒贴”．当天中午，当小王开车返家正常行驶时，突然发现有行人横穿马路，他立即脚踩制动将车刹住，由于刹车及时，避免了一场车祸．小王对“远离酒精珍爱生命”有了更深的体会．分析回答下列问题：

（1）请判断这一“急刹车反射”属于条件反射还是非条件反射？______．

（2）完成反射的结构，称为______，它由五部分组成．参与该反射的感受器是______；它的作用是______．

（3）行人反射来的光线进入司机眼球成像的先后顺序是（填序号）______．

①角膜   ②晶状体   ③视网膜   ④瞳孔  ⑤玻璃体

（4）在大脑皮层的神经中枢中，至少有______中枢和______中枢参与了该反射．

（5）我国交通法规明确规定禁止酒后开车，原因是酒精对人的______有麻痹作用，使其不能准确地协调身体的运动，以至影响行车安全．

Years ago, when I first started building websites for newspapers, many journalists told me that they saw the Internet as the end of reliable journalism. Since anyone could publish whatever they wanted online, "real journalism" would be overwhelmed, they said. Who would need professional reporters and editors if anyone could be a reporter or an editor I would tell them not to worry. While my personal belief is that anyone can be a reporter or editor, I also know that quality counts. And that the "viral" nature of the Internet means that when people find quality, they let other people know about it. Even nontraditional media sites online will survive only if the quality of their information is trusted. The future of online news will demand more good reporters and editors, not fewer.
So I was intrigued when Newsweek recently published a story called Revenge of the Expert. It argued that expertise would be the main component of "Web 3.0". "The wisdom of the crowds has peaked," says Jason Calacanis, founder of the Maholo "people-powered search engine" and a former AOL executive. "Web 3.0 is taking what we’ve built in Web 2.0—the wisdom of the crowds—and putting an editorial layer on it of truly talented, compensated people to make the product more trusted and refined." Well, yes and no. Sure, it is important for people to trust the information they find online. And as the Newsweek article argues, the need for people to find trusted information online is increasing, thus the need for more expertise. But the article fails to mention the most important feature of the world of digital information. It’s not expertise—it’s choice.
In many cases the sites that people come to trust are built on nontraditional models of expertise. Look at sites like Digg. com, Reddit. com, or Slashdot. com. There, users provide the expertise on which others depend. When many users select a particular story, that story accumulates votes of confidence, which often lead other users to choose that story. The choices of the accumulated community are seen as more trustworthy than the "gatekeeper" model of traditional news and information. Sometimes such sites highlight great reporting from traditional media. But often they bring forward bits of important information that are ignored (or missed) by "experts". It’s sort of the "open source" idea of information—a million eyes looking on the Web for information is better than a few.
Jay Rosen, who writes the PressThink blog, says in an e-mail that he’s seen this kind of story before, calling it a "kind of pathetic" trend reporting. "I said in 2006, when starting NewAssignment. Net, that the pest editorial combinations will be pro-am. I still think that. Why Because for most reporters covering a big sprawling beat, it’s still true what Dan Gillmor said. ’My readers know more than I do.’ And it’s still the case that tapping into that knowledge is becoming more practical because of the Internet."
J. D. Lasica, a social-media strategist and former editor, also says he sees no departure from the "wisdom of the crowds" model. "I’ve seen very little evidence that the sweeping cultural shifts we’ve seen in the past half dozen years show any signs of retreating," Mr. Lasica says. "Young people now rely on social networks...to take cues from their friends on which movies to see, books to read... And didn’t ’Lonely Planet Guide’ explore this terrain for travel and Zagat’s for dining back in the ’90s"
In many cases, traditional media is still the first choice of online users because the reporters and editors of these media outlets have created a level of trust for many people— but not for everyone. When you combine the idea of expertise with the idea of choice, you discover nontraditional information sites that become some of the Internet’s most trusted places. Take SCOTUSblog. com, written by lawyers about cases in the Supreme Court. It has become the place to go for other lawyers, reporters, and editors to find in-depth information about important cases. The Internet also allows individuals to achieve this level of trust. For instance, the Scobleizer. corn blog written by Robert Scoble. Mr. Scoble, a former Microsoft employee and tech expert, is widely seen as one of the most important people to read when you want to learn what’s happening in the world of technology. He built his large audience on the fact that people trust his writing.
To me, it’s the best of all possible information worlds.

What is the major argument of the passage

A．With the development of digital technology, anyone can be a reporter or editor.

B．Professional reporters and editors are always the trusted "gatekeeper" of traditional news and information.

C．The choices of the accumulated online users should be considered more trustworthy and reliable than those of the few with expertise.

D．Expertise would be the main component of both traditional media and nontraditional information sites.

供热式机组的类型有哪些？