Melissa and Love Letter made use of the trust that exists between friends or colleagues. Imagine receiving an (26) from a friend who asks you to open it. This is what happens with Melissa and several other similar email (27) . Upon running, such worms usually proceed to send themselves out to email addresses from the victim’s address book, previous emails, web pages (28) .
As administrators seek to block dangerous email attachments through the recognition of well-known (29) , 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 (30) access to your network.

A．names

B．cookies

C．software

D．extensions

鸡油菌这种野生蘑菇生长在宿主树下，如在道氏杉树的底部生长。道氏杉树为它提供生长所需的糖分。鸡油菌在地下用来汲取糖分的纤维部分为它的宿主提供养料和水。由于它们之间这种互利关系，过量采摘道氏杉树根部的鸡油菌会对道氏杉树的生长不利。
以下哪项，如果为真，将对题干的论述构成质疑

A．在最近的几年中，野生蘑菇的产量有所上升。

B．鸡油菌不只在道氏杉树底部生长，也在其他树木的底部生长。

C．很多在森林中生长的野生蘑菇在其他地方无法生长。

D．对某些野生蘑菇的采摘会促进其他有利于道氏杉树的蘑菇的生长。

E．如果没有鸡油菌的滋养，道氏杉树的种子不能成活。