Answer: billions of types of proteins
Answer:
Cohesion: Hydrogen Bonds Make Water Sticky
Explanation:
Cohesion: Hydrogen Bonds Make Water Sticky
In the case of water, hydrogen bonds form between neighboring hydrogen and oxygen atoms of adjacent water molecules. The attraction between individual water molecules creates a bond known as a hydrogen bond.
The immune system, and the excretory system
(Honestly, all of them work to keep us 'healthy', but I believe these are the ones you're looking for)