本题考查美国的节日。Memorial Day is observed on the last Monday of May. It originally honored the people killed in the American Civil War, but has become a day on which the American dead of all wars are remembered.阵亡将士纪念日原本用来纪念美国在内战中牺牲的人们，如今已成为纪念在所有战争中牺牲的美国人民的节日。