Task: Question Answering
Input (English): Passage: In September 1939, Britain entered the Second World War, which lasted until 1945. During the war, many of London's children were evacuated to avoid the frequent aerial bombing. The suggestion by senior politician Lord Hailsham that the two princesses should be evacuated to Canada was rejected by Elizabeth's mother, who declared, "The children won't go without me. I won't leave without the King. And the King will never leave." Princesses Elizabeth and Margaret stayed at Balmoral Castle, Scotland, until Christmas 1939, when they moved to Sandringham House, Norfolk. From February to May 1940, they lived at Royal Lodge, Windsor, until moving to Windsor Castle, where they lived for most of the next five years. At Windsor, the princesses staged pantomimes at Christmas in aid of the Queen's Wool Fund, which bought yarn to knit into military garments. In 1940, the 14-year-old Elizabeth made her first radio broadcast during the BBC's Children's Hour, addressing other children who had been evacuated from the cities. She stated: "We are trying to do all we can to help our gallant sailors, soldiers and airmen, and we are trying, too, to bear our share of the danger and sadness of war. We know, every one of us, that in the end all will be well." Question: When did Britain enter WWII?
Output (English): September 1939