Users also need (71) systems to help them explore the web and discover interesting data sources and interfaces that support different query and search paradigms.

A．IGMP
B．ICMP
C．CDMA
D．WAP

A．服务攻击是针对某种特定网络的攻击
B．非服务攻击是针对网络层协议而进行的
C．主要的渗入威胁有特洛伊木马和陷井
D．潜在的网络威胁主要包括窃听、通信量分析、人员疏忽和媒体清理等