Answer:
The cilia is one of the things that act defensively in the respiratory system.
Explanation:
It propels a mucus-like liquid that covers the airway which traps pathogens (potentially infectious microorganisms) and other particles, preventing them from reaching the lungs.
It could damage vessels and other parts of the body.
Amino acids are essentially the "building blocks" of proteins. You could think of it as an individual amino acid combining with others to form a link or stand.
Explanation:
Protein I think is the answer for this question.
A downhill skier traveling down a hill has a large amount of kinetic energy because of their mass and high velocity.