In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
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Question: The city state form of government eventually expanded to an?, Context: The period known as classical antiquity began with the rise of the city-states of Ancient Greece. Greek influence reached its zenith under the expansive empire of Alexander the Great, spreading throughout Asia.

Answer: empire


Question: Why do birds possess gizzards?, Context: Like the reptiles, birds are primarily uricotelic, that is, their kidneys extract nitrogenous waste from their bloodstream and excrete it as uric acid instead of urea or ammonia through the ureters into the intestine. Birds do not have a urinary bladder or external urethral opening and (with exception of the ostrich) uric acid is excreted along with feces as a semisolid waste. However, birds such as hummingbirds can be facultatively ammonotelic, excreting most of the nitrogenous wastes as ammonia. They also excrete creatine, rather than creatinine like mammals. This material, as well as the output of the intestines, emerges from the bird's cloaca. The cloaca is a multi-purpose opening: waste is expelled through it, most birds mate by joining cloaca, and females lay eggs from it. In addition, many species of birds regurgitate pellets. Males within Palaeognathae (with the exception of the kiwis), the Anseriformes (with the exception of screamers), and in rudimentary forms in Galliformes (but fully developed in Cracidae) possess a penis, which is never present in Neoaves. The length is thought to be related to sperm competition. When not copulating, it is hidden within the proctodeum compartment within the cloaca, just inside the vent. The digestive system of birds is unique, with a crop for storage and a gizzard that contains swallowed stones for grinding food to compensate for the lack of teeth. Most birds are highly adapted for rapid digestion to aid with flight. Some migratory birds have adapted to use protein from many parts of their bodies, including protein from the intestines, as additional energy during migration.

Answer: contains swallowed stones for grinding food to compensate for the lack of teeth


Question: What caused the location change?, Context: In 1926, Universal opened a production unit in Germany, Deutsche Universal-Film AG, under the direction of Joe Pasternak. This unit produced three to four films per year until 1936, migrating to Hungary and then Austria in the face of Hitler's increasing domination of central Europe. With the advent of sound, these productions were made in the German language or, occasionally, Hungarian or Polish. In the U.S., Universal Pictures did not distribute any of this subsidiary's films, but at least some of them were exhibited through other, independent, foreign-language film distributors based in New York, without benefit of English subtitles. Nazi persecution and a change in ownership for the parent Universal Pictures organization resulted in the dissolution of this subsidiary.

Answer:
Hitler's increasing domination of central Europe