Questão de Língua Inglesa

The sentences: “In 2010, a nationally representative study suggested that hearing loss among adolescents had increased to 19.5 percent in 2005-2006 from 14.9 percent in 1988-1994.” (lines 135-139) and “But a new analysis by The Wirecutter, a product recommendations website owned by The New York Times Company, has found that half of 30 sets of children’s headphones tested did not restrict volume to the promised limit.” (lines 12-17) respectively contain a/an