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

种植固定桥（）

A.可以自行摘戴的固定桥

B.固位力主要来自粘接材料的粘接力的固定桥

C.一端的固位体为固定连接，另一端的固位体为活动连接的固定桥

D.以各种骨内种植体作为固定桥的支持和固位端制成的固定桥

E.被称为完全固定桥