(6分)推断:将黑色粉末A和无色液体B混合,生成一种无色无味的气体C;加热暗紫色

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问题:

(6分)推断:将黑色粉末A和无色液体B混合,生成一种无色无味的气体C;加热暗紫色固体E,可同时得到A和C;无色气体C能使带火星的木条复燃。若将银白色金属D放在盛有C的集气瓶中燃烧,火星四射,生成一种黑色固体F,并放出热量。试推断A、B、C、D、E、F各是什么物质?

A       B        C       D       E        F      

考点:氧气的制取和收集氧气的用途氧气的工业制法自然界中的氧循环
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Education is one of the key words of our time. A man, without an education, many of us believe, is an unfortunate victim of unfortunate circumstances deprived of one of the greatest twentieth-century opportunities. Convinced of the importance of education, modern states "invest" in institutions of learning to get back "interest" in the form of a large group of enlightened young men and women who are potential leaders. Education, with its cycles of instruction so carefully worked out, is punctuated by textbooks--those purchasable wells of wisdom--what would civilization be like without its benefits

So much is certain: that we would have doctors and preachers, lawyers and defendants, marriages and births; but our spiritual outlook would be different. We would lay less stress on "facts and figures" and more on a good memory, on applied psychology, and on the capacity of a man to get along with his fellow-citizens. If our educational system were fashioned after its bookless past we would have the most democratic form of "college" imaginable. Among the people whom we like to call savages all knowledge inherited by tradition is shared by all; it is taught to every member of the tribe so that in this respect everybody is equally equipped for life.

It is the ideal condition of the "equal start" which only our most progressive forms of modern education try to reach again. In primitive cultures the obligation to seek and to receive the traditional instruction is binding on all. There are no "illiterates"--if the term can be applied to peoples without a script--while our own compulsory school attendance became law in Germany in 1642, in France in 1806, and in England 1976, and is still non-existent in a number of "civilized" nations. This shows how long it was before we considered it necessary to make sure that all our children could share in the knowledge accumulated by the "happy few" during the past centuries. Education in the wilderness is not a matter of monetary means. All are entitled to an equal start. There is none of the hurry that, in our society, often hampers the full development of a growing personality. There, a child grows up under the ever-present attention of his parents; therefore the jungles and the savages know of no "juvenile delinquency". No necessity of making a living away from home results in neglect of children, and no father is confronted with his inability to "buy" an education for his child.

Notes: juvenile delinquency 青少年犯罪。

It can be inferred from the text that()

A. some families now can hardly afford to send their children to school

B. everyone today has an equal opportunity in education

C. every country invests heavily in education

D. we are not very certain whether preachers are necessary or not

题型:填空题
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题型:填空题

按沿海与内地两大块来安排区域分工格局,这种形式的优点是( )。

A.能反映出我国的区域经济发展水平的梯度差异

B.划分后的区内一致性与区际差异性较为明显

C.有利于调动各级政府的积极性

D.有利于在全国范围内实现劳动地域分工

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何谓胎儿窘迫?其病因有哪些?

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晶体三极管的噪声有哪几种?

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