Which of the following describes a response to external stimuli?
a boy sneezes when exposed to cat dander
a girl eats food when she is hungry
a child becomes hyperactive due to a chemical imbalance
a person yawns when oxygen levels in the blood are low
a boy sneezes when exposed to cat dander
a girl eats food when she is hungry
a child becomes hyperactive due to a chemical imbalance
a person yawns when oxygen levels in the blood are low