题干

如图,分别以直角△ABC的斜边AB,直角边AC为边向△ABC外作等边△ABD和等边△ACE,F为AB的中点,DE与AB交于点G,EF与AC交于点H,∠ACB=90°,∠BAC=30°.给出如下结论:

①EF⊥AC;②四边形ADFE为菱形;③AD=4AG;

④FH=

1
4
BD其中正确结论的为____(请将所有正确的序号都填上).
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答案(点此获取答案解析)

①③④

同类题2

阅读下面的文字,完成下列各题

    词就其本来性质而言是歌辞,是广义上的诗歌的一种。

    中国古代的诗歌,向来同音乐有相当密切的关系。如《诗经》的全部和《楚辞》的一部分,以及汉魏六朝乐府诗,原来都是配乐歌唱的。但随着新的音乐和新的歌辞的出现,原来的歌辞往往成为纯粹的文字作品,譬如《诗经》到了汉代,汉乐府到了六朝,都只有少数还在传唱。而六朝人和唐人所写的古乐府诗,也都只用于诵读。

    汉魏六朝主要的音乐系统为“清商乐”,而到了隋、唐,形成了一种新的音乐系统——燕乐。它是由西域流入的“胡乐”(尤其是龟兹乐)和汉族原有的以清商乐为主的各种音乐相融而产生的。“燕乐”至唐代大盛,其歌辞起初叫做“曲子词”,后来简称为“词”。在唐代,不少文人诗歌(尤其是七绝)被伶伎直接用来配合音乐歌唱,如《乐府诗集》所录《水调》的第七段,就是杜甫的七绝《赠花卿》。但以齐言的诗入曲必然有不相合的,为了适应曲调格式,就需要做一定的变动处理,如破句、重叠、和声等,这样才能和长短不齐的曲拍相合。与此同时,也有人一开始就按照曲拍的要求来写作歌辞。近代在敦煌发现了一批唐代民间曲子词的抄本,这些歌辞的句式大多是长短不齐的,在字数、平仄等方面似尚无严格规定。一般把这种曲子词视为词的原始形态。词形态完全稳定以后,是一种具有严密的格律形式、句式参差不齐的诗体。每首词都有以词牌命名的词调,表明词写作时所依据的曲调乐谱,规定了一首词的文字格律:依乐章结构分片,依曲拍断句,依乐声高下用字。到后来,词和音乐脱钩,词成为书面文学,词牌就只表示文字的格律形式了。

    词能成为宋代文学成就的主要代表,当然不可能仅仅取决于其音乐特征和句式上的变化,更取决于它在抒情表现上的某些特征。诗的发展历史很长,功能也复杂,词则具有更为单纯的抒情性。而且,在苏轼、辛弃疾那种 “豪放派”出现以前,词很少像诗那样触及严肃、沉重、宏大的主题,它关注的主要是男女欢爱、相思别离、风花雪月之类。这些更具有个人性的、与日常生活更贴近的情感内容,在词中获得充分的表现。诗的语言通常追求精练,常用浓缩和跳跃的笔法,所以很难在细节上展开。而词的表达更为浅显和委婉曲折,意脉的流动较为连贯,因而能够将情感呈现得更为细微。像温庭筠《更漏子》的下阕写“梧桐树,三更雨,不道离情正苦。一叶叶,一声声,空阶滴到明”,在诗中是不可能出现的。

    词的长短句格式,也不能只看到它与音乐的关系。参差错落的节奏本来是由音乐旋律决定的,但同时,这样的形式也更适合上述抒情偏向的需要。

    古人有一种习惯的说法,把词称为“诗余”。“余”者,余绪之谓也,诗中说不尽的、不便说的,就拿到词中来说。在古人一般的观念中,词较为轻巧、浅俗,格调不如诗高雅,有点小看它。但正因为如此,词的写作更少拘束,更为自由。而对于喜好和擅长写作词的诗人来说,则未必有轻视的意识。

同类题5

阅读理解

    Why do you go to the library? For books, yes--but you like books because they tell stories. You hope to get lost in a story or be transported into someone else's life. At one type of library, you can do just that--even though there's not a single book.

    At a Human Library, instead of books, you can “borrow” people. Individuals volunteer as human “books” and participants in the event can “read” the book--meaning they would have a one-on-one conversation with the volunteer and share in a dialogue about that individual's experience. “Books” are volunteers from all walks of life who have experienced discrimination (歧视) based on race, religion, class, gender identity, age, lifestyle choices, disability and other aspects of their life

    For a certain amount of time, you can ask them questions and listen to their stories, which are as fascinating and as attractive as any you can find in a book. Many of the stories have to do with some kind of stereotype. You can speak with a refugee (难民), a soldier suffering from PTSD, a homeless person or a woman living with HIV. The Human Library encourages people to challenge their own long-held beliefs-to truly get to know, and learn from someone they might otherwise make a quick judgment about.

    According to its website, the Human Library is “a place where difficult questions are expected, appreciated and answered.” It provides the opportunity for the community to share and understand the experiences of others in their community.

    The Human Library Organization came to be in Copenhagen, Denmark in 2000. Ronni Abergel, his brother Dany, and some colleagues hosted a four-day event during a major Northern European festival, hoping to raise awareness about violence among youth. After the success of this event, Abergel founded the Human Library Organization, which has been growing ever since.

    Though there are a few permanent human libraries, most aren't places at all, but events. Though many do take place at physical libraries, you don't need a library card—anyone can come and be part of the experience. There have been human library events all over the globe, in universities and in pubs, from Chicago to Tunis to Edinburgh to San Antonio.

    The stories these "books" tell range from fascinating to heartbreaking and everything in between. And that's the very point of the organization--to prove that no person can be summed up in just one word. It seeks to show people that you truly can't judge a book by its cover---or by its title or label.

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