Someone make me happy am depress

Why is it a good idea to leave an interview being courteous and polite?

The kurt vonnegut commencement speech, the neiman-marcus chocolate chip cookie recipe, and the get-well emails to the dying boy are examples of select one: a. social engineering b. hoax emails c. email viruses d. worms

In a response of approximately 50 words, explain why it would be essential for the successful a/v technician to participate in additional coursework, presentations and seminars offered by equipment manufacturers as well as annual conferences attended by colleagues in the industry.