题干

若θ是任意实数,则方程x2+4y2cosθ+π
4
=1所表示的曲线一定不是 (   )

A:圆

B:双曲线

C:直线

D:抛物线

上一题 下一题 0.0难度 选择题 更新时间:2017-04-04 04:49:31

答案(点此获取答案解析)

D

同类题2

阅读下面的文章,按要求回答问题。
                                                                                               周庄:世俗文化的启示
                                                                                                         徐卓人
         “周庄的商业气息太浓了!”听见一些游过周庄的人这么说,似乎尽兴之后还带着一种遗憾。我觉得,这是把周庄理解错了,当成了桃花源。不过我听到这样的感叹倒是欣慰,因为我从受众者那里看到了世俗文化的力量。
         周庄从来不是桃花源,“商业气息”是说对了,周庄从来是个商业繁华的集镇,可以说,没有商业,就没有周庄,与今天许多享誉中外的名镇、名城一样。
        雏形的周庄与村落相差无几,到了1127年金十二相公随宋高宗南渡,落泊到这里时,人烟才逐渐稠密。后来来了个颇有传奇色彩的江南富豪沈万三的父亲沈佑,那还是在元朝中叶,沈家因为经商逐渐发迹,带动了南北市河两岸的商业,形成了以南北市河为主的旧集镇,及至明清时期,镇廓扩大,人气更旺,南北西河道两侧渐成列肆,江南大镇形成矣。
         不能否认巨商沈万三的作用。沈万三看来是个有经济头脑又思想开放的商人,周庄天然而原本封闭的水道在他的眼光里都变成了致富的途径,利用白岘江西接京杭大运河、东北接浏河的优势,干起了出海贸易的大事来,他这一干,不仅使自己富甲天下,竟将周庄变成了一个粮食、丝绸等手工业品的集散地和交易中心,促使周庄的手工业和商业迅速发展起来。周庄的丝绸、刺绣、竹器、脚炉还有白酒原本都是“藏在深闺人未识”,从此就这样沿着古河道   风风火火的出海去了。商事的频繁又呼唤出大量的旅社、客店、饭庄,周庄焉能不繁华?
          写到这里,我忽然想起了山西平遥,这里有票号“日升昌”,作家余秋雨把它称作“中国大地各式银行的‘乡下祖父’”,后来这里终于成了山西财富的中心之地,从今日平遥这些苍老而森严的高墙、精雅的屋宇走过,可以想见这里是如何人丁兴旺,繁荣红火,无数的商人“驮载着金钱,驮载着骄傲,驮载着九州的风俗和方言,驮载出一个南来北往经济血脉的大流畅”。他们留下了什么?是代表着中国金融发展史经典的洋洋120万字的《山西票号史》,是今天被联合国列入“世界文化遗产”的山西平遥!
         还记得明清时期与徽商、晋商、闽商、粤商并驾齐驱称雄中国商坛“东山帮”吗?今天你踏上这块吴中福地感受到最多的是什么?庭园的美丽,建筑的恢宏,历代状元的华光,总括说,是享用不完的文化。
         如果再扯到苏州这座古城,这话题就更贴近也更丰富了,只消说一句:如果没有姑苏的繁华史,就没有吴文化的辉煌。
         我们无法否认商业在整体文化中的重要作用,并且发现这其实是文化很重要的一部分,也就是商业文化。周庄的前景不仅来自曾经有过的商业繁荣,我发现,今天乃至将来重要的还仍然是商业文化,这是本色,也就是特色,个性。你不见,周庄所有的居民几乎与其他集镇都不同?那一排排永远保持着整齐而油亮的饰板,那一扇扇永远干净而敞亮的街窗,意味着什么?那些水巷,原本不是为了搭建在那里留给今天的旅游者看的,哪怕“船从家中过”的经典之作也只是为了买卖的方便,可以说,周庄的民居,从来不为精庐怡老,也不为金屋藏娇。这个热闹的地方,不是叫人清心寡欲,而是生的乐趣,人,好世俗之乐也!
        今天走过周庄每一条街,发现真的还是户户经商,家家开店呀,与当年红火的景象相比,只是换了一种形态。这于周庄,是多么妥贴!
这是一种世俗的文化,血肉的人须臾离不开世俗文化,人间的烟火总是最具亲和力,最符合生态的七情六欲,当然也是最人性的,如果这样,又何必要把周庄生硬地认作桃花源呢?
         找准自己的位置真的很重要,这包括创造者和欣赏创造的人。

同类题5

根据短文理解,选择正确答案。

    The timer is running. These people have 60 minutes to escape (逃脱) from a room they paid to be locked inside.

    It is a game with clues (线索) that are spread in the room. And there is no starting point. You start wherever you feel like. It is up to you to put the clues together in order to find the key to get out.

    A popular room offered by Timothy Smith in Washington D.C. is designed to mimic (模仿) the Oval Office in the White House. It is built like the office of the American president. The fun part of Escape the Oval Office is that anything here could be a clue to solving the puzzle. An old typewriter from the 1930s. Or the small table in the corner. Or the map of Washington D.C. on the wall. And then there are hidden messages that can only be seen under a black light.

    Sometimes, the telephone rings. “Would you guys like a clue?” The boss controls the game progress on a camera and calls to offer hints (提示) when needed.

    Teams can be made up of classmates, families, tourists, or a group of six friends and two strangers who just meet before the game starts.

    It's said that there are more than 800 Escape Room adventures in Washington D.C.. Each experience has different themes and stories. The rules for playing are similar, and solving the puzzle needs social, physical abilities and quick, creative thinking.

    It was a little stressful. Some of the clues seemed really complex (复杂的). But it was a lot of fun, and the players had no idea what to expect. 

    Escape Room adventure is popular because it gives any person a chance to be a detective or to be a James Bond. However, like most team sports, this game is really all about being a good teammate and having a good time.