In order to qualify for a license, a gym teacher must have a minimum of a bachelor's degree and pass competency examinations covering both general education and topics pertaining to their area of specialty. After a teacher is licensed, they must also meet continuing education requirements set by their state.
Mistake #3: Keeping mixed formula out too long. Formula that is sitting out at room temperature must be thrown away after 1 hour. If it is in the refrigerator, pre-mixed formula (also called ready-to-feed formula) that is opened must be thrown out after 48 hours. Formula that you mixed must be thrown out after 24 hours. Mistake #4: Re-using leftover formula.
A bottle is supposed to be fresh for 28 days after you take it out of the fridge and start using it. As long as it wasn't in direct sunlight you should be okay. Cold insulin kind of hurts when you inject it-I never store mine in the fridge except the bottles I haven't opened yet.