Problem: Please answer a question about the following article about Madonna (entertainer):
Madonna has sold more than 300 million records worldwide. The Guinness World Records acknowledged her as the best-selling female recording artist and the fourth best-selling act of all time, behind The Beatles, Elvis Presley, and Michael Jackson. According to the Recording Industry Association of America (RIAA), she is the best-selling female rock artist of the 20th century and the second top-selling female albums artist in the United States, with 64.5 million certified albums. Madonna is the most certified artist of all time in United Kingdom, with 45 awards from the British Phonographic Industry (BPI) as of April 2013. Billboard named Madonna as the top touring female artist of all time. She is also the highest grossing solo touring artist, with over $1.31 billion in concert gross, starting from the Blond Ambition World Tour; she first crossed a billion gross with The MDNA Tour. Overall, Madonna ranks third on all-time top-grossing Billboard Boxscore list, with just The Rolling Stones ($1.84 billion) and U2 ($1.67 billion) ahead of her. Madonna has been honored with 20 MTV Video Music Awards—the most for any artist—including the lifetime achievement Video Vanguard Award in 1986.
Who is the best selling female rock artist in the 20th century?
A: Madonna
Problem: Please answer a question about the following article about Pharmaceutical industry:
The top ten best-selling drugs of 2013 totaled $75.6 billion in sales, with the anti-inflammatory drug Humira being the best-selling drug worldwide at $10.7 billion in sales. The second and third best selling were Enbrel and Remicade, respectively. The top three best-selling drugs in the United States in 2013 were Abilify ($6.3 billion,) Nexium ($6 billion) and Humira ($5.4 billion). The best-selling drug ever, Lipitor, averaged $13 billion annually and netted $141 billion total over its lifetime before Pfizer's patent expired in November 2011.
How much money did Lipitor make before the patent expired?
A: $141 billion
Problem: Please answer a question about the following article about Hydrogen:
Lavoisier produced hydrogen for his experiments on mass conservation by reacting a flux of steam with metallic iron through an incandescent iron tube heated in a fire. Anaerobic oxidation of iron by the protons of water at high temperature can be schematically represented by the set of following reactions:
How did Lavoisier produce hydrogen for his experiments?
A: reacting a flux of steam with metallic iron through an incandescent iron tube heated in a fire
Problem: Please answer a question about the following article about Tucson, Arizona:
Cycling is popular in Tucson due to its flat terrain and dry climate. Tucson and Pima County maintain an extensive network of marked bike routes, signal crossings, on-street bike lanes, mountain-biking trails, and dedicated shared-use paths. The Loop is a network of seven linear parks comprising over 100 mi (160 km) of paved, vehicle-free trails that encircles the majority of the city with links to Marana and Oro Valley. The Tucson-Pima County Bicycle Advisory Committee (TPCBAC) serves in an advisory capacity to local governments on issues relating to bicycle recreation, transportation, and safety. Tucson was awarded a gold rating for bicycle-friendliness by the League of American Bicyclists in 2006.
Why is cycling popular in Tucson?
A:
its flat terrain and dry climate