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问题 单项选择题

患儿3岁。发热恶寒，鼻塞流涕，微咳，兼见脘腹胀满，不思乳食，呕吐酸腐，大便臭秽，舌苔厚腻。其诊断是

A．风热感冒

B．时行感冒

C．感冒夹痰

D．感冒夹惊

E．感冒夹食滞

答案

参考答案：E

问答题

设随机变量


求：(Ⅰ)二维随机变量(X，Y)的概率分布；
(Ⅱ)X和Y的相关系数ρXY；
(Ⅲ)PXY=0的值．
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单项选择题

Melissa and Love Letter made use of the trust that exists between friends or colleagues. Imagine receiving an (66) from a friend who asks you to open it. This is what happens with Melissa and several other similar email (67) . Upon running, such worms usually proceed to send themselves out to email addresses from the victim’ s address book ,previous emails, web pages (68) .
As administrators seek to block dangerous email attachments through the recognition of well- known (69) , virus writers use other extensions to circumvent such protection. Executable (.exe) files are renamed to . bat and . cnd 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 (70) access to your network.

A．attachment

B．paeket

C．datagram

D．message
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