I put 100 points into this.. Are there any parts of the human body that get oxygen directly from the air and not from the blood?

What sentence best supports the statement that hormones are involved in the regulation of homeostasis? a. the hormone erythropoeitin increases the production of red blood cells when oxygen levels are low. b. the hormone oxytocin promotes labor contractions of the uterus during childbirth. c. the hormone melatonin induces sleep and its production is slowed by exposure to light. d. the hormone cortisol suppresses the immune system and is produced when the body is under stress.

The smallest parts of these that retain their original properties are called

Where is most of the fresh water on earth found a in the ocean b in glaciers and in ice caps c in rivers d in the soil