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问题 选择题

除去下列物质中含有的少量杂质，所用除杂试剂合理的是（　　）

选项物质杂质除杂试剂
AO2CO2灼热的铜网
BNaClNa2CO3稀H2SO4
CKClMnO2加水过滤
DCaOCaCO3稀HCl

A．A

B．B

C．C

D．D

答案

A、灼热的铜网会与氧气反应生成氧化铜，把原物质除去，故不可行．

B、碳酸钠和硫酸反应生成硫酸钠，会给氯化钠中带入新的杂质，故不可行．

C、根据氯化钾可溶，二氧化锰不溶于水的性质，可以用加水过滤的方法除去二氧化锰，方法可行．

D、氧化钙和碳酸钙都能和稀盐酸反应，会把原物质也除去，故不可行．

故选C

单项选择题

With hundreds of millions of electronic（）taking place daily, businesses and organizations have a p incentive to protect the（）of the data exchanged in this manner, and to positively ensure the（）of those involved in the transactions. This has led to an industry-wide quest for better, more secure methods for controlling IT operations, and for deploying p security mechanisms deeply and broadly throughout networked infrastructures and client devices. One of the more successful concepts to engage the imaginations of the security community has been the development of standards-based security（）that can be incorporated in the hardware design of client computers. The principle of encapsulating core security capabilities in（）and integrating security provisions at the deepest levels of the machine operation has significant benefits for both users and those responsible for securing IT operations.

businesses and organizations have a p incentive to protect the（）of the data exchanged in this manner.

A．operation

B．completeness

C．integrity

D．interchange
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单项选择题 B1型题

五苓散与麻黄汤中使用桂枝的相同意义是（）

A.发散风寒

B.温经散寒

C.温阳化气

D.温阳复脉

E.平冲降逆
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