1.   Clements discovered that the lung uses this slippery, detergent-like molecule to prevent the lung tissues from sticking together when the lungs expand and contract.

2.   Emphysemic lungs gradually expand, giving victims a characteristic barrel-shaped chest.

3.   If the lung is expanding, the radiation bouncing off it is pushed closer together, slightly raising its frequency.

4.   Once the tadpole astronauts were able to get breaths, he said their lungs expanded to normal.