Problem: Predation:

Predatory animals often use their usual methods of attacking prey to inflict or to threaten grievous injury to their own predators. The electric eel uses the same electric current to kill prey and to defend itself against animals (anacondas, caimans, egrets, jaguars, mountain lions, giant otters, humans, dogs, and cats) that ordinarily prey upon fish similar to an electric eel in size; the electric eel thus remains an apex predator in a predator-rich environment. A predator small enough to be prey for others, the domestic cat uses its formidable teeth and claws as weapons against animals that might confuse a cat with easier prey. Many non-predatory prey animals, such as a zebra, can give a strong kick that can maim or kill, while others charge with tusks or horns.

What are a few predators of giant otters?
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A: unanswerable

Problem: Military history of the United States:

Fighting on one side was a coalition of forces including the Republic of Vietnam (South Vietnam or the "RVN"), the United States, supplemented by South Korea, Thailand, Australia, New Zealand, and the Philippines. The allies fought against the North Vietnamese Army (NVA) as well as the National Liberation Front (NLF, also known as Viet communists Viet Cong), or "VC", a guerrilla force within South Vietnam. The NVA received substantial military and economic aid from the Soviet Union and China, turning Vietnam into a proxy war.

The VIC operated in what geographic area?
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A: unanswerable

Problem: Arsenal F.C.:

The return of former player George Graham as manager in 1986 brought a third period of glory. Arsenal won the League Cup in 1987, Graham's first season in charge. This was followed by a League title win in 198889, won with a last-minute goal in the final game of the season against fellow title challengers Liverpool. Graham's Arsenal won another title in 199091, losing only one match, won the FA Cup and League Cup double in 1993, and a second European trophy, the European Cup Winners' Cup, in 1994. Graham's reputation was tarnished when he was found to have taken kickbacks from agent Rune Hauge for signing certain players, and he was dismissed in 1995. His replacement, Bruce Rioch, lasted for only one season, leaving the club after a dispute with the board of directors.

In what year did Arsenal win their second European cup?
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A: 1994

Problem: 51st state:

Puerto Rico has been discussed as a potential 51st state of the United States. In a 2012 status referendum a majority of voters, 54%, expressed dissatisfaction with the current political relationship. In a separate question, 61% of voters supported statehood (excluding the 26% of voters who left this question blank). On December 11, 2012, Puerto Rico's legislature resolved to request that the President and the U.S. Congress act on the results, end the current form of territorial status and begin the process of admitting Puerto Rico to the Union as a state.

What percentage of voters supported Congress?
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A:
unanswerable