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Different societies apply differing criteria regarding who is classified as "black", and these social constructs have also changed over time. In a number of countries, societal variables affect classification as much as skin color, and the social criteria for "blackness" vary. For example, in North America the term black people is not necessarily an indicator of skin color or majority ethnic ancestry, but it is instead a socially based racial classification related to being African American, with a family history associated with institutionalized slavery. In South Africa and Latin America, for instance, mixed-race people are generally not classified as "black." In South Pacific regions such as Australia and Melanesia, European colonists applied the term "black" or it was used by populations with different histories and ethnic origin.

What factors can affect the classification of "blackness"?
Answer: societal variables
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Copper is biostatic, meaning bacteria will not grow on it. For this reason it has long been used to line parts of ships to protect against barnacles and mussels. It was originally used pure, but has since been superseded by Muntz metal. Similarly, as discussed in copper alloys in aquaculture, copper alloys have become important netting materials in the aquaculture industry because they are antimicrobial and prevent biofouling, even in extreme conditions and have strong structural and corrosion-resistant properties in marine environments.

Name a property that makes copper a good material to use in marine environments?
Answer: corrosion-resistant
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The AEA's work progressed to heavier-than-air machines, applying their knowledge of kites to gliders. Moving to Hammondsport, the group then designed and built the Red Wing, framed in bamboo and covered in red silk and powered by a small air-cooled engine. On March 12, 1908, over Keuka Lake, the biplane lifted off on the first public flight in North America.[N 24] [N 25] The innovations that were incorporated into this design included a cockpit enclosure and tail rudder (later variations on the original design would add ailerons as a means of control). One of the AEA's inventions, a practical wingtip form of the aileron, was to become a standard component on all aircraft. [N 26] The White Wing and June Bug were to follow and by the end of 1908, over 150 flights without mishap had been accomplished. However, the AEA had depleted its initial reserves and only a $15,000 grant from Mrs. Bell allowed it to continue with experiments. Lt. Selfridge had also become the first person killed in a powered heavier-than-air flight in a crash of the Wright Flyer at Fort Myer, Virginia, on September 17, 1908.

How many accident-free flights had the AEA taken by 1909?
Answer:
150