$1.$ What criteria are used to classify grinding processes, and how do these criteria affect the choice of grinding operations for various materials and shapes?

$2.$ How is workpiece stability maintained in the centerless grinding process, considering its fundamental principles?

$3.$ The choice between honing and lapping depends on application requirements. What factors determine this choice?

$4.$ In precision machining applications, controlling tool contact is critical. How is this control achieved and maintained, and what are the benefits in terms of precision and surface quality?