干燥速度和干燥强度的概念?
参考答案:
干燥速度——指单位时间内,单位干燥面积上所能蒸发的水分量(kg/㎡•h)
干燥强度——指单位时间内所蒸发的水分量
香豆素类成分如果能水解后发生Gibb反应,说明具有
A.3位OH
B.4位OH
C.5位无取代
D.6位无取代
E.7位无取代
Melissa and LoveLetter made use of the trust that exists between friends or colleagues. Imagine receiving an (6) from a friend who asks you to open it. This is what happens with Melissa and several other similar email (7) . Upon running, such worms usually proceed to send themselves out to email addresses from the victim’s address book, previous emails, web pages (8) .
As administrators seek to block dangerous email attachments through the recognition of well-known (9) , 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 (10) access to your network.
8()
A.memory
B.caches
C.ports
D.registers