The kidneys make two main hormones, vitamin D and erythropoietin. Vitamin D is essential for a number of different functions in the body. Most of the vitamin D that is in the blood is inactive and it is modified by the kidney and other tissues to activate it.
1. B A reduction in competition.
2. C. Respiratory system
Answer:
No they are not the same...
Explanation:
The study is called Ecology
