Well once again, the trainer is not going to be looking for some highly technical item to find your weakness in system knowledge, he will want to see how you operate under the gun so to speak, fuel and diversion planning, safety and crew coordination, crew duty limitations, minimum crew required. Things more on an operational level, for instance, if a long departure delay takes place for whatever reason, what is the minimum fuel you can still depart with (before having to return to the gate), things of this nature, he knows you already know how to fly.