The teacher used visual aids as nonverbal teaching materials to explain complex concepts to the students.
老师使用视觉辅助工具作为非口语教材来向学生解释复杂的概念。
Interactive whiteboards are an example of nonverbal teaching materials that enhance student engagement.
互动白板是非口语教材的一个例子，它增强了学生的参与度。