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.
What was the first city to get an underground metro system? Cities all over the world have underground transportation systems (Paris Metro, London Underground, NYC subway), but what city was first? Or had the first well-developed underground transportation system?