体内摄取过量的磷、汞、砷、苯等化学物质引起的鼻出血的原因（）

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问题单项选择题 A1/A2型题

A.凝血障碍

B.血小管损伤

C.破坏造血系统

D.内源性凝血酶原减少

E.药物过敏

答案

参考答案：C

单项选择题

Science is a dominant theme in our culture. Since it touches almost every facet of our life, educated people need at least some acquaintance with its structure and operation. They should also have an understanding of the subculture in which scientists live and the kinds of people they are. An understanding of general characteristics of science as well as specific scientific concepts is easier to attain if one knows something about the things that excite and frustrate the scientist.
This book is written for the intelligent student or lay person whose acquaintance with science is superficial; for the person who has been presented with science as a musty storehouse of dried facts; for the person who sees the chief objective of science as the production of gadgets; and for the person who views the scientist as some sort of magician. The book can be used to supplement a course in any science, to accompany any course that attempts to give an understanding of the modern world, or independent of any course -- simply to provide a better understanding of science. We hope this book will lead readers to a broader perspective on scientific attitudes and a more realistic view of what science is, who scientists are, and what they do. It will give them an awareness and understanding of the relationship between science and our culture and an appreciation of the roles science may play in our culture. In addition, readers may learn to appreciate the relationship between scientific views and some of the values and philosophies that are pervasive in our culture.
We have tried to present in this book an accurate and up-to-date picture of the scientific community and the people who populate it. That population has in recent years come to comprise more and more women. This increasing role of women in the scientific subculture is not an unique incident but, rather, part of the trend evident in all segments of society as more women enter traditionally male-dominated fields and make significant contributions. In discussing these changes and contributions, however, we are faced with a language that is implicitly sexist, one that uses male nouns or pronouns in referring to unspecified individuals. To offset this built-in bias, we have adopted the policy of using plural nouns and pronouns whenever possible and, when absolutely necessary, alternating he and she. This policy is far from being ideal, but it is at least an acknowledgment of the inadequacy of our language in treating half of the human race equally.
We have also tried to make the book entertaining as well as informative. Our approach is usually informal. We feel, as do many other scientists, that we shouldn’t take ourselves too seriously. As the reader may observe, we see science as a delightful pastime rather than as a grim and dreary way to earn a living.

According to this passage, ______.

A．English is a sexist language

B．only in the scientific world is the role of women increasing rapidly

C．women are making significant contributions to eliminating the inadequacy of our language

D．male nouns or pronouns should not be used to refer to scientists

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填空题

碳酸锂广泛应用于陶瓷和医药等领域。已-锂辉石(主要成分为Li_2^O·Al₂O₃·4SiO₂)为原材料制备Li₂CO₃的工艺流程如下：

已知：Fe³⁺、Al³⁺、Fe²⁺和Mg²⁺以氢氧化物形式完全沉淀时，溶液的PH分别为3.2、5.2、9.7和12.4；Li₂SO₄、LiOH和Li₂CO₃在303K下的溶解度分别为34.2g、12.7g和1.3g.

(1)步骤Ⅰ前，已-锂辉石要粉碎成细颗粒的目的是_____________。

(2)步骤Ⅰ中，酸浸后得到的酸性溶液中含有Li⁺、SO₄^2-_，另含有Al³⁺、Fe³⁺、Fe²⁺、Mg²⁺、Ca²⁺、Na⁺等杂质，需在搅拌下加入_____________(填“石灰石”、“氯化钠”或“稀硫酸”)以调节溶液的PH到6.0~6.5，沉淀部分杂质离子，然后分离得到浸出液。

(3)步骤Ⅱ中，将适量的H₂O₂溶液、石灰乳和Na₂CO₃溶液依次加入浸出液中，可除去的杂质金属离子有______________。

(4)步骤Ⅲ中，生成沉淀的离子方程式为________________。

(5)从母液中可回收的主要物质是_____________。

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