短语词组短语cat flu virus 猫流感病毒flu virus antigen 流感病毒抗原bird flu virus 禽流感病毒the flu virus 流感病毒swine flu virus 猪流感病毒flu virus strain 流感病毒株h n flu virus h5n1 流感病毒seasonal flu virus 季节性流感病毒flu virus fm 流感病毒fm 返回 flu virus