英语语法分析

Swine pox, which belongs to the pox disease complex, is caused by two antigenically different poxviruses .

猪痘属于痘病群，是由两种抗原上不同的痘病毒引起的。

In the present study, H9N2 viruses isolated from chicken, duck and other minor poultry were genetically and antigenically characterized.

最近的研究中，H9N2病毒从具有遗传和抗原相似特点的小鸡、鸭和少数其他家禽中被分离出来。

It is estimated that more than 90 antigenically different strains of known types of respiratory viruses cause the common cold syndrome[4].

据估计，在已知的呼吸道病毒中有90种以上抗原不同的菌株能引起感冒综合征。