历史发展既有传承又有创新。下表所列信息,按朝代(唐、宋、元、明)先后排列正确的是( )
① | 通政司、复社、都察院、风力水车 |
② | 政事堂、北门学士、内作使绫匠、高转筒车 |
③ | 枢密院、土司、木活字、监察御史 |
④ | 中书门下、三司使、《武经总要》、草市 |
从某企业生产的某种产品中抽取100件,测量这些产品的一项质量指标值,由测量表得如下频数分布表:
质量指标值分组 |
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洒水车的水箱是一个横放的椭圆柱体,尺寸如图,当水箱装满水时,计算水箱的一个端面所受的总压力.
Since the days of Aristotle, a search for universal principles has characterized the scientific enterprise. In some ways, this quest for commonalities defines science. Newton’s laws of motion and Darwinian evolution each bind a host of different phenomena into a single explicatory frame work.
(1) In physics, one approach takes this impulse for unification to its extreme, and seeks a theory of everything—a single generative equation for all we see. It is becoming less clear, however, that such a theory would be a simplification, given the dimensions and universes that it might entail. Nonetheless, unification of sorts remains a major goal.
This tendency in the natural sciences has long been evident in the social sciences too.(2) Here, Darwinism seems to offer justification. For if all humans share common origins, it seems reasonable to suppose that cultural diversity could also be traced to more constrained beginnings. Just as the bewildering variety of human courtship rituals might all be considered to be forms of sexual selection, perhaps the world’s languages, music, social and religious customs and even history are governed by universal features. (3) To filter out what is unique from what is shared might enable us to understand how complex cultural behaviour arose and what guides it in evolutionary or cognitive terms.
That, at least, is the hope. But a comparative study of linguistic traits published online today supplies a reality check. Russell Gray at the University of Auckland and his colleagues consider the evolution of grammars in the light of two previous attempts to find universality in language.
The most famous of these efforts was initiated by Noam Chomsky, who suggested that humans are born with an innate language-acquisition capacity that dictates a universal grammar. A few generative rules are then sufficient to unfold the entire fundamental structure of a language, which is why children can learn it so quickly.
(4) The second, by Joshua Greenberg, takes a more empirical approach to universality, identifying traits (particularly in word order) shared by many languages, which are considered to represent biases that result from cognitive constraints.
Gray and his colleagues have put them to the test by examining four family trees that between them represent more than 2,000 languages. (5) Chomsky’s grammar should show patterns of language change that are independent of the family tree or the pathway tracked through it, whereas Greenbergian universality predicts strong co-dependencies between particular types of word-order relations. Neither of these patterns is borne out by the analysis, suggesting that the structures of the languages are lineage-specific and not governed by universals.
洒水车的水箱是一个横放的椭圆柱体,尺寸如图,当水箱装满水时,计算水箱的一个端面所受的总压力.
洒水车的水箱是一个横放的椭圆柱体,尺寸如图,当水箱装满水时,计算水箱的一个端面所受的总压力.
一批产品的二等品率为,从这批产品中每次随机取一件,有放回地抽取次.表示抽到的二等品件数,则 __________.
洒水车的水箱是一个横放的椭圆柱体,尺寸如图,当水箱装满水时,计算水箱的一个端面所受的总压力.
海水养殖场进行某水产品的新、旧网箱养殖方法的产量对比,收获时各随机抽取了个网箱,测量各箱水产品的产量(单位:),其频率分布直方图如图:
(Ⅰ)设两种养殖方法的箱产量相互独立,记表示事件“旧养殖法的箱产量低于,新养殖法的箱产量不低于”,估计的概率;
(Ⅱ)填写下面列联表,并根据列联表判断是否有的把握认为箱产量与养殖方法有关:
箱产量 | 箱产量 | |
旧养殖法 | ||
新养殖法 |
(Ⅲ)根据箱产量的频率分布直方图,求新养殖法箱产量的中位数的估计值(精确到).
附:
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洒水车的水箱是一个横放的椭圆柱体,尺寸如图,当水箱装满水时,计算水箱的一个端面所受的总压力.
洒水车的水箱是一个横放的椭圆柱体,尺寸如图,当水箱装满水时,计算水箱的一个端面所受的总压力.
洒水车的水箱是一个横放的椭圆柱体,尺寸如图,当水箱装满水时,计算水箱的一个端面所受的总压力.