Q: Extract the answer to the question from the following context. Question: What was the system to replace AI? Context: Airborne Interception radar (AI) was unreliable. The heavy fighting in the Battle of Britain had eaten up most of Fighter Command's resources, so there was little investment in night fighting. Bombers were flown with airborne search lights out of desperation[citation needed], but to little avail. Of greater potential was the GL (Gunlaying) radar and searchlights with fighter direction from RAF fighter control rooms to begin a GCI system (Ground Control-led Interception) under Group-level control (No. 10 Group RAF, No. 11 Group RAF and No. 12 Group RAF).
A: GCI system

Q: Extract the answer to the question from the following context. Question: What is significant of the scientific study? Context: Even though there is a broad scientific agreement that essentialist and typological conceptualizations of race are untenable, scientists around the world continue to conceptualize race in widely differing ways, some of which have essentialist implications. While some researchers sometimes use the concept of race to make distinctions among fuzzy sets of traits, others in the scientific community suggest that the idea of race often is used in a naive or simplistic way,[page needed] and argue that, among humans, race has no taxonomic significance by pointing out that all living humans belong to the same species, Homo sapiens, and subspecies, Homo sapiens sapiens.
A: argue that, among humans, race has no taxonomic significance by pointing out that all living humans belong to the same species, Homo sapiens, and subspecies, Homo sapiens sapiens

Q: Extract the answer to the question from the following context. Question: How did Eisenhower avoid paying the personal tax rate? Context: In 1948, Eisenhower became President of Columbia University, an Ivy League university in New York City. The assignment was described as not being a good fit in either direction. During that year Eisenhower's memoir, Crusade in Europe, was published. Critics regarded it as one of the finest U.S. military memoirs, and it was a major financial success as well. Eisenhower's profit on the book was substantially aided by an unprecedented ruling by the U.S. Department of the Treasury that Eisenhower was not a professional writer, but rather, marketing the lifetime asset of his experiences, and thus he only had to pay capital gains tax on his $635,000 advance instead of the much higher personal tax rate. This ruling saved Eisenhower about $400,000.
A: ruling by the U.S. Department of the Treasury

Q: Extract the answer to the question from the following context. Question: How many shows were shown each week prior to season 14? Context: The continuing decline influenced further changes for season 14, including the loss of Coca-Cola as the show's major sponsor, and a decision to only broadcast one, two-hour show per week during the top 12 rounds (with results from the previous week integrated into the performance show, rather than having a separate results show). On May 11, 2015, prior to the fourteenth season finale, Fox announced that the fifteenth season of American Idol would be its last. Despite these changes, the show's ratings would decline more sharply. The fourteenth season finale was the lowest-rated finale ever, with an average of only 8.03 million viewers watching the finale.
A:
two