Best Answer - Chosen by the Asker
I think, and also had experience in as a teacher, that the best
is that the teacher does its job at its best, and the students feel free
to ask questions (with some consideration for the clock on the wall) and
they actively participate in solving problems at the blackboard, or
similar activities.
All in all, each has its proper role.
The teacher should have consideration for the motivations the students have for undertaking the effort.
Several times, I just skipped all students' questions that were not specific
to the subject as time was precious, and that was the ground of a good
relation.
Also remember: skip occasions to laugh only when really necessary,
but don't turn a serious thing as the class environment into entertainment;
this would be detrimental to the serious and motivated learner, which should always
be respected.
