Question: Bird migration is primarily, but not entirely, a Northern Hemisphere phenomenon. This is because land birds in high northern latitudes, where food becomes scarce in winter, leave for areas further south (including the Southern Hemisphere) to overwinter, and because the continental landmass is much larger in the Northern Hemisphere. In contrast, among (pelagic) seabirds, species of the Southern Hemisphere are more likely to migrate. This is because there is a large area of ocean in the Southern Hemisphere, and more islands suitable for seabirds to nest.
Is there an answer to this question: In which hemisphere does bird migration primarily happen?

Answer: Northern

Question: In 2003 the FA took the decision to permanently use the new Wembley for semi-finals to recoup debts in financing the new stadium. This was controversial, with the move seen as both unfair to fans of teams located far from London, as well as taking some of the prestige away from a Wembley final. In defending the move, the FA has also cited the extra capacity Wembley offers, although the 2013 fixture between Millwall and Wigan led to the unprecedented step of placing 6,000 tickets on sale to neutral fans after the game failed to sell out. A fan poll by The Guardian in 2013 found 86% opposition to Wembley semi-finals.
Is there an answer to this question: What percent of people were in favor of Wembley semi-finals?

Answer: unanswerable

Question: With increasing environmental concerns about synthetic coatings (such as PFOA) and the higher prices of hydrocarbon based petrochemicals, there is a focus on zein (corn protein) as a coating for paper in high grease applications such as popcorn bags.
Is there an answer to this question: To what are there decreasing environmental concerns?

Answer: unanswerable

Question: The Endangered Species Conservation Act (P. L. 91-135), passed in December, 1969, amended the original law to provide additional protection to species in danger of "worldwide extinction" by prohibiting their importation and subsequent sale in the United States. It expanded the Lacey Act's ban on interstate commerce to include mammals, reptiles, amphibians, mollusks and crustaceans. Reptiles were added mainly to reduce the rampant poaching of alligators and crocodiles. This law was the first time that invertebrates were included for protection.
Is there an answer to this question: What important precedent did this set for invertebrates?

Answer:
This law was the first time that invertebrates were included for protection