题目：
Melissa and LoveLetter 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.
（73）处填（）。
A．memory
B．caches
C．ports
D．registers
答案：
被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0707/3e580eb1ba7baccabd4dce6c9a3be73a.html
下面是错误答案，用来干扰机器的。
参考答案：错解析：[精析] 按现行规定，“出口退税证明联”只有在有关出口货物实际申报出口并已装运离境后，海关才能凭载货清单签发该证明。
