搜题请搜索小程序“爱下问搜题”
问题 选择题

下列关于碳酸氢铵的叙述不正确的是（　　）

A．碳酸氢铵是一种白色的固态物质

B．在通常情况下，碳酸氢铵固体应敞开盛放

C．堆放碳酸氢铵化肥的仓库常常有一股刺激性的气味

D．加热碳酸氢铵固体可以发现固体逐渐减少，同时会产生具有刺激性气味的气体

答案

A、碳酸氢铵是一种白色的固态物质，正确；

B、碳酸氢铵受热易分解，易挥发，有强烈的刺鼻、熏眼氨味，故不可敞开盛放，故错误；

C、碳酸氢铵有强烈的刺鼻、熏眼氨味，所以堆放碳酸氢铵化肥的仓库常常有一股刺激性的气味，故正确；

D、碳酸氢铵受热易分解，温度越高分解越快，有强烈的刺鼻、熏眼氨味，所以D正确．

故选B

单项选择题

Public Key Infrastructure (PKI) service providers offer organizations fully integrated PKI-managed services designed to secure Intranet, Extranet, Virtual Private Network (VPN), and e-commerce applications. PKI solutions can enable a number of security services, including p authentication and non-repudiation of transactions.
eToken enables the users of PKI systems to generate and store (101) and digital certificates inside the token, creating a secure environment and allowing full portability and maximum ease of use. eToken Pro can also perform sensitive on-chip (102) operations, ensuring that users’ keys axe never exposed to the PC environment, eToken eliminates the need to store (103) and keys on a hard disk or browser file, or to transmit them across the Internet/Extranet; assuring peace-of-mind and confidence during online communications.
A digital signature is created using the private key of an individual to ensure the Validity of his request. This technology can be used to guarantee (104) of various transactions. The strength of either the authentication level or the digital signature relies on the level of protection offered to the private key. eToken Pro offers the maximum level of security, since it enables the use of the private key for signing and authenticating inside the eToken.
The most secure use of authentication involves enclosing at least one certificate with every signed message. The message (105) verifies the certificate using the CA’s public key. If the sender’s public key is legitimate, the recipient verifies the message’s signature. Digital signatures created with a private key are verified with the digital certificate containing the public key.

A．interpretation

B．detection

C．encryption

D．translation
查看答案
问答题 简答题

新中国成立后，谁第一个喊出了毛 * * 万岁？
查看答案