The graph shows the change in temperature of a sample of water in a closed system as thermal energy is added over time.
150°C -
100°C
Temperature (°C)
50°C
0°C-
-50°C
10
50
60
20 30 40
Time (min)
What happens to the temperature of the water when it begins to melt?

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.