某医师调查得10名女中学生体重X (kg)与肺活量Y(L)，经直线回归分析知，b＝0

女，50岁，临床以黄疸就诊，CT示胆囊增大，内有结石，胆总管扩张，在胰头段略细而突然中断，增强扫描见胆总管下段壁明显增厚且有强化，应考虑

A．急性胆囊炎

B．胆总管结石

C．硬化性胆管炎

D．胆总管下段癌

E．急性胰腺炎假性囊肿

警告治安处罚由（）决定，要制作处罚决定书，向违反治安管理行为人宣布并交给本人。

A.公安派出所

B.公安机关

C.国家安全机关

D.审判机关

成立行政服务中心，把过去“群众围着政府转”转变为“政府围着群众转”，坚决克服了“门难进，脸难看，人难找，事难办”的不良现象。这种做法主要体现政府工作原则是（）。

A.民主集中制

B.依法治国

C.对人民负责

D.法律面前一律平等

CRH2型动车组自动解编后头罩无法关闭，可以操作司机室的（）进行闭合。

A、连挂准备

B、空挡

C、停放

D、分合控制盘

Remember Second Life, the virtual world that was supposed to become almost as important as the first one Now populated by no more than 84,000 avatars at a time, it has turned out to be a prime example of how short-lived Internet fads can be. Yet if many adults seem to have given up on virtual worlds, those that cater to children and teenagers are thriving. Several have even found a way to make money.

In America, nearly 10 million children and teenagers visit virtual worlds regularly, estimates eMarketer, a market researcher-a number the firm expects to increase to 15 million by 2013．As in January, there were 112 virtual worlds designed for under-18s with another 81 in development, according to Engage Digital Media, a market research firm.

All cater to different age groups and tastes. In Club Penguin, the market leader, which was bought by Disney in 2007 for a whopping $ 700 million, primary-school children can take on a penguin persona, fit out their own igloo and play games. Habbo Hotel, a service run from Finland, is a global hangout for teenagers who want to customise their own rooms and meet in public places to attend events. Gala Online, based in Silicon Valley, offers similar activities, but is visited mostly by older teens who are into Manga comics.

Not a hit with advertisers, these online worlds earn most of their money from the sale of virtual goods, such as items to spruce up an avatar or a private room. They are paid for in a private currency, which members earn by participating in various activities, trading items or buying them with real dollars.

This sort of stealth tax seems to work. At Gala Online, users spend more than $1 million per month on virtual items, says Craig Sherman, the firm’s chief executive. Running such a virtual economy is not easy, which is why Gaia has hired a full-time economist to grapple with problems that are well known in the real world, such as inflation and an unequal distribution of wealth.

There are other barriers that could limit the growth of virtual worlds for the young, but the main one is parents. Many do not want their offspring roaming virtual worlds, either because they are too commercial or are thought to be too dangerous. Keeping them safe is one of the biggest running costs, because their sponsors have to employ real people to police their realms.

Youngsters are also a fickle bunch, says Simon Levene of Accel Partners, a venture- capital firm. Just as children move from one toy to another, they readily switch worlds or social networks, often without saying goodbye.

Even so, Debra Aho Williamson, an analyst at eMarketer, believes "these worlds are a training ground for the three-dimensional web". If virtual worlds for adults, which so far have been able to retain only hardcore users, manage to hang on for a few years, they may yet have a second life.

What can we infer from Simon Levene’s comments（）

A. Young people will usually change games

B. Young people are only attracted by the novelties in the games

C. Game companies will have to use various measures to keep young people continuing playing their games

D. Current prosperity of online games market may not last long due to the capriciousness of young people