When preparing to expose a molar bitewing with a bite tab, p…

When preparing to expose a molar bitewing with a bite tab, placing your index finger along the molar buccal or occlusal surfaces  will help you to visualize the curvature of the _______ and align the _______ .  These procedures will help you to achieve correct _______ angulation in the molar area and to direct the central ray through the _______