Did you ever ask yourself this question: When they give safety instructions on an airplane, they always tell me to put on my mask first before assisting others. Why? The fact is, if oxygen becomes unavailable because of sudden depressurization of the cabin, every second counts. We put our masks on first because, if we do not, we will pass out in just a few seconds. Then they always tell us that if we are instructed to leave the airplane, we do so - and we do so fast. We do no