关于有核红细胞表述正确的是 （）

A.正常成人外周血涂片中偶见

B.1周之内婴儿血涂片中仅可见到少量

C.外周血涂片中出现常表示红系增生减低

D.巨幼红细胞贫血外周血涂片中罕见

E.急性白血病患者的外周血涂片中不会见到

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.

（71）处填（）。

A．attachment

B．packet

C．datagram

D．message