生产经营单位是安全生产的( )，国家有关法律法规对生产经营单位加强安全规章制度建设有明确的要求。

A．执行者

B．执行主体

C．责任主体

D．实施者

Basically, a firewall is a (145) process or a set of integrated processes that runs on a router or (146) to control the flow of networked application traffic (147) through it. Typically, firewalls are placed on the entry point to a (148) network such as the Internet. They could be considered traffic cops. The firewall’s (149) is to ensure that all communication between an organization’s network and the Internet conform to the organization’s policies.

A．browser

B．client

C．repeater

D．server