Shoulder is called Deltoid
upper back is called cutaneous pectoris
I believe the answer would be embryo, larva, pupa
I think the best choice to fill in the blank would be disengagement. It is a theory in aging that perceives aging as an inevitable occurrence which results in decreased social interaction between the people in the society and the person. Hope this helps.
Which blood cell? that would be the white blood cells they are amorphous and change into various shapes to engulf their prey and digest them!! some kind also cause clumping preventing spreading of the host other than those cells antibodies might cause a huge fuss they might spot me as an antigen and may trigger response like coughing that might just send me flying out of the system!!