Most computer systems are (71) to two different groups of attacks：insider attacks and outsider attacks．A system that is known to be (72) to an outsider attack by preventing (73) from outside can still be vulnerable to the insider attacks accomplished by abusive usage of (74) users．Detecting such abusive usage as well as attacks by outsides not only provides information on damage assessment,but also helps to prevent future attacks．These attacks are usually (75) by tools referred to as Intrusion Detection Systems．

（75）处填（）。

A．searched

B．checked

C．tested

D．detected

下列现象中，不能用分子模型解释的是 [ ]

A．1升水和1升酒精混合后体积小于2升

B．用杯子盛清水，无论怎样倒，总有少量水残留在杯壁上

C．走进公园，一股花香扑鼻而来

D．在阳光下可以见到鱼缸里的金鱼在不停地游动