Problem: Birds need to alter their metabolism in order to meet the demands of migration. The storage of energy through the accumulation of fat and the control of sleep in nocturnal migrants require special physiological adaptations. In addition, the feathers of a bird suffer from wear-and-tear and require to be molted. The timing of this molt - usually once a year but sometimes twice - varies with some species molting prior to moving to their winter grounds and others molting prior to returning to their breeding grounds. Apart from physiological adaptations, migration sometimes requires behavioural changes such as flying in flocks to reduce the energy used in migration or the risk of predation.
How do birds store energy?
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Answer: through the accumulation of fat and the control of sleep

Problem: Home-based manufacturing operations were active year round. Families willingly deployed their children in these income generating home enterprises. In many cases, men worked from home. In France, over 58 percent of garment workers operated out of their homes; in Germany, the number of full-time home operations nearly doubled between 1882 and 1907; and in the United States, millions of families operated out of home seven days a week, year round to produce garments, shoes, artificial flowers, feathers, match boxes, toys, umbrellas and other products. Children aged 514 worked alongside the parents. Home-based operations and child labour in Australia, Britain, Austria and other parts of the world was common. Rural areas similarly saw families deploying their children in agriculture. In 1946, Frieda Miller - then Director of United States Department of Labour - told the International Labour Organisation that these home-based operations offered, "low wages, long hours, child labour, unhealthy and insanitary working conditions."
What time were home manufactoring activities for children taking place?
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Answer: year round

Problem: The eleven prefecture-level divisions of Zhejiang are subdivided into 90 county-level divisions (36 districts, 20 county-level cities, 33 counties, and one autonomous county). Those are in turn divided into 1,570 township-level divisions (761 towns, 505 townships, 14 ethnic townships, and 290 subdistricts). Hengdian belongs to Jinhua, which is the largest base of shooting films and TV dramas in China. Hengdian is called "China's Hollywood".
How many prefecture-level divisions of Zhejiang are there?
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Answer:
eleven