NAC’s (Network Access Control) role is to restrict network access to only compliant endpoints and（）users. However, NAC is not a complete LAN（）solution; additional proactive and（） security measures must be implemented. Nevis is the first and only comprehensive LAN security solution that combines deep security processing of every packet at 10Gbps, ensuring a high level of security plus application availability and performance. Nevis integrates NAC as the first line of LAN security（）. In addition to NAC, enterprises need to implement role-based network access control as well as critical proactive security measures — real-time, multilevel（）inspection and microsecond threat containment.

However, NAC is not a complete LAN（）solution.

A．crisis

B．security

C．favorable

D．excellent

CO₂和H₂的混合气体加热到850℃时，可建立下列平衡：CO₂+H₂CO+H₂O在一定温度下，反应平衡时有90％的氢气变成水，且c(CO₂)·c(H₂)＝c(CO)·c(H₂O)，则原混合气体中CO₂和H₂分子数之比是 [ ]

A．1：1

B．5：1

C．9：1

D．1：10