某工程双代号网络计划如下图，其中关键线路有（   ）条。

案例四：
Z老师在某小学担任数学教师已经多年。根据该校的管理规定，从事教学工作的教师必须在课前备课，编写教案，并在每学期期末向学校上交教案。从教时间里，Z老师先后上交教案48册。这些教案都是Z老师在参考别人教案的基础上独自创作的，且没有留底稿。Z老师多次要求谈校返还其教案，该小学却以找不到为由拒绝将教案运还给Z老师。Z老师所在学校的做法()

经行发热瘀热壅阻证的治法是

小儿泄泻的变证辨证重在辨

载脂蛋白分类

《民法典》规定，当事人就合同履行费用的负担约定不明确的，由（）一方负担。

关于伊托必利作用机制及毒副作用的说法，错误的是（   ）

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_____.

1964年，联合国召开了第一届贸易和发展会议。这次会议后诞生了一个新的国际组织，它的名字是()。

下列选项中，对民族乐器箫的归类正确的是(　　)。

SGLT-2 抑制剂的常见不良反应是