an eternal wait time
those 5-10 seconds seem internal,I bring the subject back to the place in the book to find the answer
Also one might try giving partial answers or breaking down the question. A little hint or rephrasing might help some students overcome their
hesitation to answer the question.
Perhaps interspersing those fact-type questions with questions asking opinions and personal reactions will encourage more responses.
If I do not know an answer to a question, I often have students look up the answer on their own time, learn the material, and then share their findings with their classmates during the following class.
I also challenge the students to come up with answers in a fashion that pushes their percieved knowledge of the subject
