题干

函数f(x)=2x2﹣mx+2当x∈[﹣2,+∞)时是增函数,则m的取值范围是(  )

A:(﹣∞,+∞)

B:8,+∞)

C:(﹣∞,﹣8

D:(﹣∞,8

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答案(点此获取答案解析)

C

同类题1

阅读下面一段文字,完成文后小题。

围棋与国家

林建超

围棋起源于中国,是黄河文明的产物,其形制弈法等都饱含着文明母体的基因和特征。围棋极可能源自上古时期的结绳而治、河图洛书和周易八卦,因为其形制、内涵与中华文明的源头相符。

围棋的产生和发展,始终与弈者对自然、社会和人生的思考感悟联系在一起。围棋不仅对个人修身养性,而且对民族社会的群体心理产生深刻影响。

围棋是中华五千年文明的象征,民族文化的瑰宝、高度智慧的结晶,这种地位不是任何人封赐的,也不是带有感情色彩的主观结论,而是人们在反复实践和比较中认识到的,是随着社会和文明的进步而不断深化和升华的。

围 棋的价值和地位是在与各种掷彩博累活动的比较中确立起来的。最早有文献记载的围棋活动是在春秋时期。从春秋到西汉,社会风气浮躁、趋利,具有运气性和刺激 性、宜于赌博的博累棋流行甚广,围棋处于受挤压的位置,但始终保持着顽强的生命力。东汉中期后,社会风气转变,文明程度提高,思想更为自由,人们不满足于 掷彩行棋的非公平的竞智斗巧,围棋更加受到人们的喜爱和重视,而曾经盛极一时的博累棋逐步走向衰弱,到唐代时完全消亡了。博累棋消亡的原因从根本上说是他 们不符合我们民族的思想特征,不能满足人们精神生活的真正需求,而围棋在与它们的比较中表现出了本质上的优势。

围 棋的价值和地位在与传统礼教观念斗争中确立起来的。围棋作为反映和体现人们心灵自由的智力博弈活动,在很长一段时间里,被认为不符合传统伦理观念。后来, 人们逐步认识到这些观念都是不对的。从东汉中后期到魏晋时期,人们开始从生命意义上认识围棋的价值,就把围棋作为自觉的艺术追求和精神宣寄的工具,并把它 纳入儒士必备的艺技。

围棋的价值和地位是从正反两方面的社会实践对比中确立起来的。人们在围 棋活动的实践中逐渐认识到,围棋本身具有娱乐、教育、竞技、交际等功能。弈棋活动的负面作用不能归咎于围棋本身,而是人们自己对“度”的把握不好造成的。 随着历史的发展,人们普遍肯定了围棋的功能和价值,确立了围棋在民族文化中的精髓和瑰宝地位。

对 围棋,不能神化,也不能矮化。正确认识围棋价值的出发点,应当是“国艺价值观”。所谓“国艺”,就是与国家民族有深厚渊源,上升到国家层面,能够反映民族 精神需求的艺术和技能形式。儒家开始只承认“六艺”,即礼、乐、射、御、书、数,其中没有围棋。到魏晋时人们对“艺”有了崭新的认识,突破了儒家历来只重 “六艺”的传统,把围棋纳入“艺”的范围,围棋登入“国艺”的殿堂。事实证明,围棋在民族文化中的精髓和瑰宝地位,也只有“国艺”一词才能相配。

(节选自《围棋与国家》,有删改)


同类题4

阅读理解

    Humans and gorillas shared evolution for 23 million years. Their paths separated only six million years ago. Research on how gorillas communicate can help us understand human language development.

    Understanding how the brain works helps us see a connection between language development and non-verbal signs. These signs or movements include things like the way we move our hands or bodies or the different expressions our faces have in different social situations. A new study on gorillas showed that the right side of the body is controlled by the left part of the brain and it is also the location for language development.

    Two cameras were used to film all of one ape's movements. One of the first results was that gorillas use their right hands more when they are doing actions with their heads or mouths at the same time. This shows that there is a connection between how our brain works and the reason we use one side of our body more than the other. In addition, we can use the results of the study and our knowledge about brains to help us understand more about how language first developed in humans.

    Dr Forrester, who did the study, says the results can be useful in other ways, such as understanding language development in children. For example, some children have serious illness called “autism” which can stop them communicating normally with people. It might be possible to use the same study method to find out which children have this illness when they are very young. Doctors will then be able to start treatment early.