1) Pneumothorax in this case; a spontaneous pneumothorax can be life threatening cause the lung will eventually cause vacuum used by the lung to fill with air, and as you constantly expand your lung it decreases and collapses. So C is going to be the answer.
2) Acetylcholine is the hormone responsible for the "Rest and digest". It is the direct opposite of the Fight and Flight reaction which is marked in Bronchodilation, Increased HR, and increased BP. B
3) Secretin is responsible for stimulating the release of bile by the liver. Secretin is released by the duodenum, the junction of the stomach and small intestines. B
Clay because it’s a mixture of dirt and runoff/water
D - an increase in tree cover in the tundra.
Chromosomal deletion is the loss of genetic code, caused by a segment of chromosome breaking away during DNA replication. The best answer is the third one, "when part of a chromosome breaks off and does not reattach."