Number 4 would be your answer. hope this helped!!!
I believe that the one about animal/based proteins is the false one
JoAnn has a cold. She is coughing up mucus (a respiratory secretion) from her lungs. JoAnn is the (blank) in the chain of transmission. The mucus from her cough is the (blank) in the chain of transmission.
The mucus from her cough is getting all of the germs out of her system.
Abt PE? Can u be a tad more specific?