What is the science behind being able to feel pain and fear?

When the person is unconscious, using oxygen, confused or disoriented, has facial trauma, is likely to have a seizure, is younger than 6 years old, has sores, redness, swelling, or pain in the mouth. i hope this .

The answer is c) urethra

Immunization is the introduction of a foreign substance to provoke  the immune response system.  immunizations are the same as vaccinations. it introduces foreign (but dead/ weakened) illnesses to train the body to fight against them. specific viruses and bacteria have specific antigens, antigens act sort of like name tags. these name tags the immune system recognize what's dangerous to the body and what's safe.