The Cisco ASA Security Appliance can offer benefit of integrating which three security services into one device？（） [" IPS"," VPN Concentrator"," ACS server"," PIX firewall"," CSA MC"," DDoS Anomaly Guard and Detector"]
试述等密度离心法及其特点。
盈余管理的主体是（）。 ["公司管理当局","公认会计原则","会计估计","会计方法"]
与从价税相比，从量税（） ["在商品价格上涨时保护作用更强","在商品价格下降时保护作用更强","能够体现公平税负原则","目前被大多数国家采用"]
中国外汇交易中心实行（） 。 ["会员制","公司制","集团制","股份制"]
块状层理
