先化简,再求值:3x+3x•(1x-1+1x+1)÷6x,其中x=3+1.

题型:解答题

问题:

先化简,再求值:
3x+3
x
•(
1
x-1
+
1
x+1
6
x
,其中x=
3
+1.
考点:分式的加减乘除混合运算及分式的化简最简二次根式
题型:解答题

“剑是维护自由的最后手段,一旦自由得到确立,就应该将它放在一旁”、“我最大的期望是看到人类的苦难——战争——自地球上消失。”这两句话反映了华盛顿 [ ]

A.捍卫自由,避免战争

B.坚持民主,警惕专制

C.不恋官位,不慕权势

D.热爱国家,鞠躬尽瘁

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(10分)按要求回答问题:

Ⅰ(1)硫酸酸化的高锰酸钾溶液与草酸反应离子方程式

(2)硫代硫酸钠与硫酸反应的化学方程式

Ⅱ工业上利用天然气(主要成分为CH4)与CO2进行高温重整制备CO,已知CH4、H2和CO的燃烧热(△H)分别为−890.3kJ∙mol1、−285. 8 kJ∙mol1和−283.0 kJ∙mol1,则生成1m3(标准状况)CO所需热量为

             kJ

Ⅲ 请写出下列物质电子式

CO2           H2O2          NH4Cl         N2H4

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关于无水乙醇用于神经破坏治疗的描述,下列哪项不正确()。

A.无水乙醇作用于神经后,3~10天起效,维持2~4个月,个别可达6~12个月

B.主要用于顽固性疼痛的治疗,如三叉神经痛、癌性疼痛和反复发作的反射性交感神经萎缩症的治疗

C.注射部位可以是局部注射,也可以经硬膜外腔和蛛网膜下腔给药

D.常用于良性疾病所致疼痛的神经毁损治疗

E.可并发运动神经和交感神经的破坏,还有部分病人出现神经再生或毁损不全的症状

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下述论断正确的是

A.设f(x)在(-∞,+∞)上有定义,除x=0外均可导,且f'(x)>0,则f(x)在(-∞,+∞)上是严格单调增加的.

B.设f(x)为偶函数且x=0是f(x)的极值点,则f'(0)=0.

C.设f(x)在x=x0处二阶导数存在,且f"(x0)>0,则x=x0是f(x)的极小值点.

D.设f(x)在x=x0处三阶导数存在,且f'(x0)=0,f"(x0)=0,f"(x0)≠0,则x=x0一定不是f(x)的极值点.

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Sofia Coppola’s "Lost in Translation" is a funny, bittersweet movie that uses cultural dislocation as a metaphor for people who have gotten lost in their own lives. The movie contains priceless slap-stick from Bill Murray, finely tuned performances by Murray and the beautiful Scarlett Johansson and a visual and aural design that cultivates a romantic through melancholy mood. In only her second feature, Coppola has made a poised, intelligent film that nicely balances laughs with a poignancy rarely seen in American movies. If Focus Features markets "Lost in Translation" carefully, this most original comedy could win audiences well beyond art houses.
Bob Harris (Murray) is a grumpy movie star in town to shoot a whiskey commercial. He is not only plagued by jet lag and gloom over a deteriorating marriage of many years, he is also in the midst of a midlife crisis that dampens his spirits but not his wit.
Charlotte (Johansson) , the neglected wife of a photographer, experiences a similar air-condl-tioned nightmare. Married two years, she already feels lost in the relationship, unable to partici-pate in her husband’s career or pinpoint what she wants out of life. When she ventures into the city, she is confronted by a distorted version of Western modernity.
These two people discover each other late at night at the bar. Neither one can sleep. A friend-ship evolves in their mutual isolation.
Coppola sees in Tokyo’s crowded, neon-lit urban landscape a society estranged from its own culture. The night is filled with pleasure-seekers obsessed by games, toys and American pop culture. Only when Charlotte takes a train to Kyoto is she able to experience the old Japan of ancient temples and gardens, tea houses and kimono-clad figures. This role fits Murray like his own skin. A middle-aged burnout who sees no challenges on his horizon gradually changes into a man revitalized by another alienated soul. His comic touch enriches the character with a self-deprecating wit and in a few sequences, a rubbery physicality that earns sustained laughs. Johansson makes Charlotte’s loneliness and disillusionment palpable as the woman is cut off from life in ways she never imagined.
Using high-speed film stock, cinematographer Lance Aeord gives the glaring neon and num-bingly sleek interiors a kind of romantic sheen. The score produced by Brian Reitzell created out of Japanese musical themes and "Tokyo dream-pop" adds to the sense of an Eastern city that has succumbed in large measure to Western culture.

Which of the following is NOT true about Bob Harris

A.He is a bad-tempered movie star.

B.He is sad because of his unhappy marriage.

C.He is a bit slow as he is in a midlife crisis.

D.He is one of Charlotte’s friends.

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