When asking questions, it is best to tell the teacher what you don't understand, whether you don't understand this idea or a specific step, why you don't understand it, or the theorem used in this step. These details can make you listen more efficiently and ask questions more easily accepted by teachers. And generally speaking, there are always other students in the class who can't do it, so don't be afraid to ask questions.

Of course, in your specific situation, you can only raise your hand and ask in a low voice. The specific questions are also based on the points I mentioned just now.