Hi Nedialka: A well prepared teacher is ready for whatwver may occur during the class. They have more than enough material to cover the period. They are able to field questions - sometimes questions and their answers can occupy a large part of class. But preparedness allows the teacher to cover what they want covered, emphsisize the needed points, and have the resources needed when that time comes. This is not going to happen by accident - the teacher will have to plan for these successful outcomes to take place. Regards, Barry