are going to have首先看到tomorrow可知是一般将来时，但后面反问句用了aren't they，可知是用一般将来时的be going to do的形式。
They (are going to have) a history lesson tomorrow,aren't they?祝你学习进步，更上一层楼！ (*^__^*) 不明白的再问哟，请及时采纳，多谢！
