Very true, it should be a priorty to be prepared. Questions, if they relate to the material being presented, should be answered with knowledge by the instructor.

Prepartation is very important.  I tend to stick closely with theh course schedule and use a running game plan to keep the class on track.  In a hands on class with many students I find that staying organized and anticipating problems keeps the classs moving.  With regards to questions...there are always questions that I feel I can't fully answer from my own knowlege-- so we look up the information together and I show them how a medical professional uses their resources!