Pulmonary surfactant is a mixture of lipids and proteins which is secreted into the alveolar space by epithelial type II cells. The main function of the surfactant is to lower the surface tension at the ir/liquid interface within the alveoli of the lung. In babies born prematurely, pulmonary surfactant may not be present in adequate amounts due to insufficient exocytosis in type II alveolar cells.
i believe its B and D as they're both acids/enzymes
The part of the river that would have animals with very muscular bodies and adaptations that survive in turbulent water is the transition zone.
