1 The pancreas is an abdominal gland situated behind the stomach in the upper abdomen.  The main function of the pancreas is to secrete hormones and enzymes that help with digestion and regulate blood sugar (glucose) metabolism.
See also: List of tram and light rail transit systems. The Shanghai Metro is the longest metro system by route length. The Beijing Subway is the metro system with the highest ridership. The New York City Subway has the most stations.
Confidence votes 9. NYC i believe New York City is the correct answer only if by longest the questioner means the longest by miles of track. The Metropolitan Transit Authority reports that the system currently has approximately 660 miles of track in revenue service - in other words, serving passengers. (Another 180 miles of track is in non-revenue service, such as in subway yards.) By that measure the system dwarfs all others in the world.