It is one of the 4 major organs
O2. because this gas is metabolized and will be more efficiently used as time goes on
Well, I wouldn't say they were developed sufficiently. Respiratory Distress Syndrome Respiratory distress syndrome (RDS) primarily occurs in infants born prematurely. Up to 50 percent of infants born between 26 and 28 weeks and fewer than 30 percent of infants born between 30 and 31 weeks develop RDS.