Motorcycle Repair: i need this for my college course, fuel air mixture, stroke work

Question
describe what is meant by two-stroke exhaust pulsations with regards to mixture retention.

Answer
Martin,
 Interesting.  I'm not really positive what "mixture retention" exactly refers to.  I would imagine it refers to the fuel air mixture that remains in the combustion chamber post ignition and how that effects the rapid regularity of 2-stroke exhaust pulses.  Possibly if incomplete ignition occurs, the pulse loses it's cadence and effects the cyclic draft/mixture flow that makes a 2-stroke work effeciently.
 Sorry I can't be of any difinitive help.  Let me know what the text book answer is when you find out, I'd be interested.

Mike