What is the most comfortable posture to sit and sleep in class?

I think if you want to sleep in class, the most comfortable way is to lie on your desk, but I still want to advise you that if you feel unwell, you'd better go to a place like the infirmary to diagnose your physical condition in advance, and don't force yourself, otherwise it will lead to a serious illness and eventually delay your time. Lie prone on the table with one hand on your arm as a pillow. This posture can avoid pressing the arm numb, and at the same time get better rest efficiency.