Gastroesophageal reflux is a common, self-limited process in infants that usually resolves by six to 12 months of age. Effective, conservative management involves thickened feedings, positional treatment, and parental reassurance.
The definition of a martyr is a person who is killed because of his beliefs (especially religious beliefs), or a person who exaggerates his sacrifice to get sympathy. A religious person who refuses to deny his religion and is killed for it is an example of amartyr.
The definition of a volunteer is  a person who donates his time or efforts for a cause or organization without being paid. A person who works in a soup kitchen for free is an example of a volunteer.