Please answer this: Question: "When was did the lab offer tours?" Context: "The FBI Laboratory, established with the formation of the BOI, did not appear in the J. Edgar Hoover Building until its completion in 1974. The lab serves as the primary lab for most DNA, biological, and physical work. Public tours of FBI headquarters ran through the FBI laboratory workspace before the move to the J. Edgar Hoover Building. The services the lab conducts include Chemistry, Combined DNA Index System (CODIS), Computer Analysis and Response, DNA Analysis, Evidence Response, Explosives, Firearms and Tool marks, Forensic Audio, Forensic Video, Image Analysis, Forensic Science Research, Forensic Science Training, Hazardous Materials Response, Investigative and Prospective Graphics, Latent Prints, Materials Analysis, Questioned Documents, Racketeering Records, Special Photographic Analysis, Structural Design, and Trace Evidence. The services of the FBI Laboratory are used by many state, local, and international agencies free of charge. The lab also maintains a second lab at the FBI Academy." Answer:
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Answer: before the move to the J. Edgar Hoover Building

Please answer this: Question: "How many Japanese ships were destroyed in the attack?" Context: "With the Japanese CAP out of position and the carriers at their most vulnerable, SBD Dauntlesses from Enterprise and Yorktown appeared at an altitude of 10,000 feet (3,000 m) and commenced their attack, quickly dealing fatal blows to three fleet carriers: Soryu, Kaga, and Akagi. Within minutes, all three were ablaze and had to be abandoned with great loss of life. Hiryu managed to survive the wave of dive bombers and launched a counter-attack against the American carriers which caused severe damage to Yorktown (which was later finished off by a Japanese submarine). However, a second attack from the U.S. carriers a few hours later found and destroyed Hiryu, the last remaining fleet carrier available to Nagumo. With his carriers lost and the Americans withdrawn out of range of his powerful battleships, Yamamoto was forced to call off the operation, leaving Midway in American hands. The battle proved to be a decisive victory for the Allies. For the second time, Japanese expansion had been checked and its formidable Combined Fleet was significantly weakened by the loss of four fleet carriers and many highly trained, virtually irreplaceable, personnel. Japan would be largely on the defensive for the rest of the war." Answer:
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Answer: four

Please answer this: Question: "When was the fourth widespread invasion of Red crossbills Loxia curvirostra across England?" Context: "Sometimes circumstances such as a good breeding season followed by a food source failure the following year lead to irruptions in which large numbers of a species move far beyond the normal range. Bohemian waxwings Bombycilla garrulus well show this unpredictable variation in annual numbers, with five major arrivals in Britain during the nineteenth century, but 18 between the years 1937 and 2000. Red crossbills Loxia curvirostra too are irruptive, with widespread invasions across England noted in 1251, 1593, 1757, and 1791." Answer:
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Answer:
1791