：下列各句中，句意明确的一句是（）。

The typical firewall consists of two packet filters and a (an)

A．router

B．bridge

C．application

D．server

The typical firewall consists of two packet filters and a(an)(68).

A．router

B．bridge

C．application

D．server

A．permit

B． accept

C． deny

D． discard

A. Set the next hop.

B. Discard packets.

C. Set loss priority.

D. Sample packet content.

A．fruiting

B．vegetative

C．flowering

D．dormant

A. The packet will be accepted and logged.

B. The packet will be discarded and logged.

C. The packet will be rejected and a syslog message generated.

D. The packet will be accepted and sampled.

A. Write more packet filters.

B. Write less packet filters.

C. Purchase a license for states.

D. Upgrade definitions manually

防火墙(FIREWALL)的主要类型包括

A. 包过滤型防火墙(PACKET FILTER)

B. 代理服务型防火墙(PROXY SERVICE)

C. 双宿主主机防火墙

D. 屏蔽主机防火墙