Reminds me of 40+ years ago when I had my oral test from the FAA examirer for my Powerplant rating. He asked me to explain the oil path thru a gear type pump. I thought that was self evident and said between the gears. He said 'which gears' and to show on a diagram-so I showed between the wide space between the teeth around the outside, but it seems that many students would point to the area where the teeth meshed?!? oh well