Problem: Antibiotics:

The emergence of resistance of bacteria to antibiotics is a common phenomenon. Emergence of resistance often reflects evolutionary processes that take place during antibiotic therapy. The antibiotic treatment may select for bacterial strains with physiologically or genetically enhanced capacity to survive high doses of antibiotics. Under certain conditions, it may result in preferential growth of resistant bacteria, while growth of susceptible bacteria is inhibited by the drug. For example, antibacterial selection for strains having previously acquired antibacterial-resistance genes was demonstrated in 1943 by the LuriaDelbruck experiment. Antibiotics such as penicillin and erythromycin, which used to have a high efficacy against many bacterial species and strains, have become less effective, due to the increased resistance of many bacterial strains.

What is the purpose of bacterial strains?
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A: unanswerable

Problem: Space Race:

In simple terms, the Cold War could be viewed as an expression of the ideological struggle between communism and capitalism. The United States faced a new uncertainty beginning in September 1949, when it lost its monopoly on the atomic bomb. American intelligence agencies discovered that the Soviet Union had exploded its first atomic bomb, with the consequence that the United States potentially could face a future nuclear war that, for the first time, might devastate its cities. Given this new danger, the United States participated in an arms race with the Soviet Union that included development of the hydrogen bomb, as well as intercontinental strategic bombers and intercontinental ballistic missiles (ICBMs) capable of delivering nuclear weapons. A new fear of communism and its sympathizers swept the United States during the 1950s, which devolved into paranoid McCarthyism. With communism spreading in China, Korea, and Eastern Europe, Americans came to feel so threatened that popular and political culture condoned extensive "witch-hunts" to expose communist spies. Part of the American reaction to the Soviet atomic and hydrogen bomb tests included maintaining a large Air Force, under the control of the Strategic Air Command (SAC). SAC employed intercontinental strategic bombers, as well as medium-bombers based close to Soviet airspace (in western Europe and in Turkey) that were capable of delivering nuclear payloads.

During what decade, did a fear of communism oversweep the US?
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A: 1950s

Problem: Bird:

Birds sometimes use plumage to assess and assert social dominance, to display breeding condition in sexually selected species, or to make threatening displays, as in the sunbittern's mimicry of a large predator to ward off hawks and protect young chicks. Variation in plumage also allows for the identification of birds, particularly between species. Visual communication among birds may also involve ritualised displays, which have developed from non-signalling actions such as preening, the adjustments of feather position, pecking, or other behaviour. These displays may signal aggression or submission or may contribute to the formation of pair-bonds. The most elaborate displays occur during courtship, where "dances" are often formed from complex combinations of many possible component movements; males' breeding success may depend on the quality of such displays.

Visual communication among birds may involve what kind of displays?
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A: ritualised displays

Problem: Mosaic:

Christian mosaic art also flourished in Rome, gradually declining as conditions became more difficult in the Early Middle Ages. 5th century mosaics can be found over the triumphal arch and in the nave of the basilica of Santa Maria Maggiore. The 27 surviving panels of the nave are the most important mosaic cycle in Rome of this period. Two other important 5th century mosaics are lost but we know them from 17th-century drawings. In the apse mosaic of Sant'Agata dei Goti (462472, destroyed in 1589) Christ was seated on a globe with the twelve Apostles flanking him, six on either side. At Sant'Andrea in Catabarbara (468483, destroyed in 1686) Christ appeared in the center, flanked on either side by three Apostles. Four streams flowed from the little mountain supporting Christ. The original 5th-century apse mosaic of the Santa Sabina was replaced by a very similar fresco by Taddeo Zuccari in 1559. The composition probably remained unchanged: Christ flanked by male and female saints, seated on a hill while lambs drinking from a stream at its feet. All three mosaics had a similar iconography.

When was the mosaic of Sant'Agata dei Goti destroyed?
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A:
1589