All the following factors affect the absorption of iron except:
a. vitamin c
b. calcium and phosphorous
c. source of the iron
d. oxygen concentration of the blood

Well, l think that some effective communication is, emotional barriers and lack of attention, interest distraction or irrelevance. also some physical disabilities such as hearing problems or speech difficulties.      l hope i am correct  and you good luck.

By placing 2 fingers at the sternum (the spot where the lower ribs meet) the put the heel of your other hand next to your fingers. hope this