Part 1. Definition
In this task, you're given a question, along with a context passage which has extra information available on certain terms mentioned in it. Your job is to determine which sentence(s) from the passage can be used to search for further information needed to answer the question.
Part 2. Example
Question: When did the operation during which the 704th dropped supplies to allied troops near Nijmegen begin? Passage: The group was occasionally diverted from strategic missions to carry out air support and interdiction missions. It supported Operation Overlord, the invasion of Normandy by attacking transportation targets, including bridges, along with airfields and strong points in France. On D Day, the squadron and the rest of the 446th Group led the first heavy bomber mission of the day. The 446th aided ground forces at Caen and Saint-Lo during July by hitting bridges, gun batteries, and enemy troops. During Operation Market Garden, the attempt to seize a bridgehead across the Rhine in the Netherlands, the 704th dropped supplies to allied troops near Nijmegen. It struck lines of communications during the Battle of the Bulge. During Operation Varsity in March 1945, it supplied ground and airborne troops near Wesel. The squadron flew its last combat mission on 25 April 1945 against Salzburg, Austria. The group had flown 273 missions and had lost 58 aircraft during the war,
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Answer: During Operation Market Garden, the attempt to seize a bridgehead across the Rhine in the Netherlands, the 704th dropped supplies to allied troops near Nijmegen.
Explanation: The passage describes the 704th's actions during Operation Market Garden.
Part 3. Exercise
Question: Which submarine did Ian McIntosh serve on first? Passage:He served aboard the submarines HMS Porpoise and HMS Thrasher earning the Distinguished Service Cross for his service in the latter in 1942. As commanding officer of the submarine HMS Sceptre he sank almost 15,000 tons of enemy shipping and took part in Operation Source, the attacks on heavy German warships in Norwegian waters by towed midget submarines. He commanded the submarine HMS Alderney from 1946, the submarine HMS Aeneas from 1950 and then the aircraft carrier in the 1960s. He became Director-General Weapons (Naval) at the Ministry of Defence in 1969 and Deputy Chief of the Defence Staff (Operational Requirements) in 1970 before retiring in 1973.

Answer:
He served aboard the submarines HMS Porpoise and HMS Thrasher earning the Distinguished Service Cross for his service in the latter in 1942