Here is a question about this article: Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting by humans, and is driven primarily by availability of food. It occurs mainly in the northern hemisphere, where birds are funnelled on to specific routes by natural barriers such as the Mediterranean Sea or the Caribbean Sea.
What is the answer to this question: Which birds migrate?
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So... Many species


Here is a question about this article: The Portuguese language is the official national language and the primary language taught in schools. English and Spanish are also part of the official curriculum. The city has six international schools: American School of Brasília, Brasília International School (BIS), Escola das Nações, Swiss International School (SIS), Lycée français François-Mitterrand (LfFM) and Maple Bear Canadian School. August 2016 will see the opening of a new international school - The British School of Brasilia. Brasília has two universities, three university centers, and many private colleges.
What is the answer to this question: What languages besides Portuguese are taught in Brasilia's schools?
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So... English and Spanish


Here is a question about this article: Mastic asphalt is a type of asphalt which differs from dense graded asphalt (asphalt concrete) in that it has a higher asphalt/bitumen (binder) content, usually around 7–10% of the whole aggregate mix, as opposed to rolled asphalt concrete, which has only around 5% added asphalt/bitumen. This thermoplastic substance is widely used in the building industry for waterproofing flat roofs and tanking underground. Mastic asphalt is heated to a temperature of 210 °C (410 °F) and is spread in layers to form an impervious barrier about 20 millimeters (0.79 inches) thick.
What is the answer to this question: What is the usual thickness of the mastic spread on roofs?
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So...
20 millimeters