加装了防护过滤器以后，这烟囟已不再散发成股的废气到大气中去了。 The chimney is no longer giving off volumes of waste gas into the atmosphere, as protective filters are being used.
代理防火墙比包过滤器防火墙易于保持更多的上下文 The proxy firewall maintain context more easily than the packet filter firewall.
内部和外部包过滤器和一台单向定位的bastion主机的配置提供很好的安全性。 The configuration of internal and external packet filter and a single home bastion host provide very good security.
在燃料进入发动机之前，过滤器先把它过滤。 The filter cleans the fuel before it enters the engine.