Britain's first use of brass occurred around the 3rd–2nd century BC. In North America, copper mining began with marginal workings by Native Americans. Native copper is known to have been extracted from sites on Isle Royale with primitive stone tools between 800 and 1600. Copper metallurgy was flourishing in South America, particularly in Peru around 1000 AD; it proceeded at a much slower rate on other continents. Copper burial ornamentals from the 15th century have been uncovered, but the metal's commercial production did not start until the early 20th century.
When did commercial production of copper begin?
early 20th century

Men's rhythmic gymnastics is related to both Men's artistic gymnastics and wushu martial arts. It emerged in Japan from stick gymnastics. Stick gymnastics has been taught and performed for many years with the aim of improving physical strength and health. Male athletes are judged on some of the same physical abilities and skills as their female counterparts, such as hand/body-eye co-ordination, but tumbling, strength, power, and martial arts skills are the main focus, as opposed to flexibility and dance in women's rhythmic gymnastics. There are a growing number of participants, competing alone and on a team; it is most popular in Asia, especially in Japan where high school and university teams compete fiercely. As of 2002[update], there were 1000 men's rhythmic gymnasts in Japan.[citation needed]
What are the main focus?
tumbling, strength, power, and martial arts skills are the main focus

In 1983, New York State Attorney General Robert Abrams filed suit in the United States District Court for the Northern District of New York to compel GE to pay for the cleanup of what was claimed to be more than 100,000 tons of chemicals dumped from their plant in Waterford, New York. In 1999, the company agreed to pay a $250 million settlement in connection with claims it polluted the Housatonic River (Pittsfield, Massachusetts) and other sites with polychlorinated biphenyls (PCBs) and other hazardous substances.
How much did GE agree to pay in claims for the pollution it caused in the Housatonic River and other sites?
$250 million