1. The professor's lecture was filled with complex equations, and most of the students sat in incomprehension.
教授的讲座充满了复杂的方程式，大部分学生都坐在那里一头雾水。

2. The foreign language was so difficult for me that I could only stare at the text in incomprehension.
对我来说，这门外语太难了，我只能呆呆地盯着课文，一头雾水。