在工作分析的方法中，能使员工和管理者相互沟通的方法是( )

A．观察法

B．访谈法

C．问卷法

D．参与法

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．

（71）处填（）。

A．vulnerable

B．week

C．helpless

D．sensitively