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问题 选择题

化学用语是学习化学的重要工具，下列表示物质变化的化学用语中，正确的是

A．电解饱和食盐水时，阳极的电极反应式为：2Cl—－2e—==Cl2↑

B．明矾净水时，主要反应的离子方程式为： Al3+＋3H2O==Al(OH)3 ↓＋3H+

C．氢硫酸的电离方程式为：H2S 2H+＋S2—

D．钢铁发生电化学腐蚀的正极反应式：Fe－2e—Fe2+

答案

答案：A

正确答案：A

A．正确，电解饱和食盐水时，阳极发生氧化反应，电极反应式为：2Cl—－2e—==Cl2↑

B．不正确，明矾净水时，主要反应的离子方程式为： Al3+＋3H2OAl(OH)3 ＋3H+

C．不正确，氢硫酸的电离方程式为：H2S H+＋HS—

D．不正确，钢铁发生电化学腐蚀的正极反应式：O2＋4 e-＋2H2O=4OH―

单项选择题

Melissa and Love Letter made use of the trust that exists between friends or colleagues.　Imagine receiving an __(71)___from a friend who asks you to open it.　This is what happens with Melissa and several other similar email __(72)___.Upon　running ,such worms usually proceed to send themselves out to email addresses from the victim's address book, previous emails, web pages__(73)___.

As administrators seek to block dangerous email attachments through the recognition of well-known ___(74)____,virus writers use other extensions to circumvent such protection.Executable (.exe) files are renamed to .bat and .cmd plus a whole list of other extensions and will still run and successfully infect target users.

Frequently ,hackers try to penetrate networks by sending an attachment that looks like a flash movie ,which, while displaying some cute animation ,simultaneously runs commands in the background to steal your passwords and give the __(75)__access to your network.

（74）处填（）。

A．names

B．cookies

C．software

D．extensions
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多项选择题

个人品德的形成（）

A.依赖于个体的社会实践

B.受历史和现实的社会关系的制约

C.过程包含多种心理成分的相应发展

D.取决于一个人在一次、两次道德行为中
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