The endocrine system is a collection of glands that regulate your metabolism, growth, sleep, mood and other things around your body.
There are many answers to your question but one way is the evaporation cycle.
Answer:
It's C. They are mostly made up of hydrogen and helium
There are lots:
Biology and Medicine - cloning and expression of human insulin in bacteria (stopped having to produce it from pig pancreases); Watson & Crick discovery of the structure of DNA; gene therapy in humans
Chemistry - determination of the exact number of molecules in a mole (Avagadro's number); discovery of radioactivity (Rutherford); the invention of nylon (DuPont); Boyle's law (behavior of gases)
