number 2 is for question 1
number 1 is for question 3
number 4 is for question 2
number 3 is for question 4
I believe the correct answer would be "different systems".
Hope it helps!
Make you feel euphoria! its a "pleasure" chemical
When stimulated, the brain stem's sneeze center orders muscle contractions from esophagus to sphincter. That includes the muscles controlling the eyelids. Some sneezers even shed a few tears. Perhaps people close their eyes while sneezing to prevent the expelled particles from entering their eyes,
