阿波罗宇宙飞船以N2H4(联氨)和N2O4为动力源,反应温度达27000C,反应

题型:选择题

问题:

阿波罗宇宙飞船以N2H4(联氨)和N2O4为动力源,反应温度达27000C,反应化学方程式为 2N2H4+N2O4=3N2+4H2O,下列关于该反应的叙述正确的是(  )

A.属于置换反应

B.属于非氧化还原反应

C.N2H4是还原剂

D.N2是氧化产物,不是还原产物

考点:氧化还原反应的本质和特征氧化还原反应的定义
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蛛网膜下腔出血最常见的病因是

A.抗凝治疗的并发症
B.脑动脉炎
C.高血压动脉硬化
D.脑血管畸形
E.先天性动脉瘤破裂

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我国现行税法规定,税务行政处罚的种类包括( )。

A.警告

B.罚款

C.没收非法所得

D.停止出口退税权

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如图甲、乙两带电小球的质量均为m,所带电量分别为q和-q,两球间用绝缘细线连接,甲球用绝缘细线悬挂在天花扳上。在两球所在空间有方向向左的匀强电场,电场强度为E.当两球平衡时细线被拉紧,此时的情景应该是(   )

题型:选择题

A.    introduction  B. company  C. accidentally   D. against    AB. sped 
AC. apparent    AD. between  BC. institutional  BD. context  CD. influenced
  Comparisons were drawn between the development of television in the 20th century and the spread of printing in the 15th and 16th centuries. Yet much had happened __47__. As was discussed before, it was not until the 19th century that the newspaper became the dominant pre-electronic medium, following in the wake of the pamphlet and the book and in the __48__ of the periodical. It was during the same time that the communications revolution __49__ up, beginning with transport, the railway, and leading on through the telegraph, the telephone, radio, and motion pictures into the 20th-century world of the motor car and the airplane. Not everyone sees that process in perspective. It is important to do so. It is generally recognized, however, that the __50__ of the computer in the early 20th century, followed by the invention of the integrated circuit during the 1960s, radically changed the process, although its impact on the media was not immediately __51__. As time went by, computers became smaller and more powerful, and they became “personal” too, as well as __52__, with display becoming sharper and storage capacity increasing. It was within the computer age that the term “information society” began to be widely used to describe the __53__ within which we now live. The communications revolution has __54__ both work and leisure and how we think and feel both about place and time, but there have been controversial views about its economic, political, social and cultural implications. “Benefits” have been weighed __55__ “harmful” outcomes. And generalizations have proved difficult.
题型:选择题

下列化学结构的药物用途为().

A.主要对间日疟,恶性疟,抢救脑型疟效果良好

B.主要用于控制疟疾症状

C.主要用于恶性疟,对耐氯喹的恶性疟尤其适用

D.主要作用于红细胞前期疟原虫和配子体,能有效地控制疟疾症状

E.主要用于预防疟疾

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