Answer:
The correct answer will be option-D
Explanation:
Pulmonary Surfactant is a complex substance produced by the pneumocytes epithelial II cells in the alveolar sac.
The surfactant is composed of the proteins and lipids which plays a role in keeping alveoli open by reducing the surface tension formed between the air and liquid.
The surfactant act by forming a monolayer surface film which helps reduce the surface tension.
Thus, option-D is the correct answer.
Sustainable forestry because the old trees are being replaced
Answer:
Main land, peninsula, and islands
Explanation:
