claim: Species distribution can be understood through at least one environmental factor.
evidence: USS Harold C. Thomas -LRB- DE-21 -RRB- was an constructed for the United States Navy during World War II .. United States Navy. United States Navy. World War II. World War II. United States. United States. It was promptly sent off into the Pacific Ocean to protect convoys and other ships from Japanese submarines and fighter aircraft .. Pacific Ocean. Pacific Ocean. convoys. convoys. Japanese. Empire of Japan. submarines. submarines. aircraft. aircraft. At the end of the war , she returned to the United States proudly with two battle stars .. United States. United States. battle stars. battle stars. She was launched on 18 December 1942 by the Mare Island Naval Shipyard , Vallejo , California , as HMS Essington -LRB- BDE-21 -RRB- for the British Royal Navy ; later designed for U.S. Navy use ; and commissioned on 31 May 1943 , Comdr. H. Reich in command .. Mare Island Naval Shipyard. Mare Island Naval Shipyard. Royal Navy. Royal Navy