Not only the students but also the teacher interested in this activity.Aam B．is C．are

问题补充：

Not only the students but also the teacher interested in this activity.

A．am B．is C．are

答案：

解析：句意:不仅学生们而且老师对这个活动感兴趣。not only… but also…不仅，而且，连接两个并列的主语时，应根据就近原则，与最近的主语保持一致，故这里应该跟the teacher 的形式保持一致，应该用单数，故选B。