When the nerd wiseguy answers anyway, he/she doesn't actually want to disrupt the teacher's flow, he/she finds the ten seconds of complete silence awkward and wants to move on to the next thing.
Seriously, it was so annoying to have to participate in the charade. I put a paperback in my pencil case, but some teachers took it personally if I read during class, and it's absolute torture to have to listen to a disengaged group stumble through an answer to a question like this with your full attention on the front of the class. As an adult nobody tries to teach you using question and answer for anything that requires more time than a first aid certificate because they know damn well that you'll leave and/or pull out your phone.
Seriously, it was so annoying to have to participate in the charade. I put a paperback in my pencil case, but some teachers took it personally if I read during class, and it's absolute torture to have to listen to a disengaged group stumble through an answer to a question like this with your full attention on the front of the class. As an adult nobody tries to teach you using question and answer for anything that requires more time than a first aid certificate because they know damn well that you'll leave and/or pull out your phone.