最大转速为（2.5～12）×104r/min的离心机称为（）。 ["超速离心机","常速离心机","高速离心机","低速离心机"]
下面哪一项港址选择原则是不对的？（） ["在平原河流顺直微弯段，宜选在凹岸深槽的下段","在山区河流非冲积性河段，宜选在急流卡口下游的缓水段和顺流区","水库港宜选在水库大坝附近","在人工运河和河网地区，宜选在河汉或洼地处"]
流行性感冒病毒分为甲、乙、丙三型的依据（） ["所致疾病的临床特征","流行特征","病毒内部和外部抗原结构不同","表面抗原血凝素"]
下列各项费用中，（）没有包含关税。 ["到岸价","抵岸价","FOB价","CIF价","增值税"]
One of your customers wishes to use the NAS to perform DHCP functions and does not currently have a Layer 3 gateway in its production network. Which gateway mode is appropriate for this customer？（） [" Virtual Gateway"," Real-IP Gateway"," NAT Gateway"," IP-IP Gateway"]
简答问卷调查的局限性。
