Article: West's third studio album, Graduation, garnered major publicity when its release date pitted West in a sales competition against rapper 50 Cent's Curtis. Upon their September 2007 releases, Graduation outsold Curtis by a large margin, debuting at number one on the U.S. Billboard 200 chart and selling 957,000 copies in its first week. Graduation once again continued the string of critical and commercial successes by West, and the album's lead single, "Stronger", garnered the rapper his third number-one hit. "Stronger", which samples French house duo Daft Punk, has been accredited to not only encouraging other hip-hop artists to incorporate house and electronica elements into their music, but also for playing a part in the revival of disco and electro-infused music in the late 2000s. Ben Detrick of XXL cited the outcome of the sales competition between 50 Cent's Curtis and West's Graduation as being responsible for altering the direction of hip-hop and paving the way for new rappers who didn't follow the hardcore-gangster mold, writing, "If there was ever a watershed moment to indicate hip-hop's changing direction, it may have come when 50 Cent competed with Kanye in 2007 to see whose album would claim superior sales."

Question: What artist was Kanye's third album release competing against?
Ans: 50 Cent


Article: In the 20th century, new types of glass such as laminated glass, reinforced glass and glass bricks have increased the use of glass as a building material and resulted in new applications of glass. Multi-storey buildings are frequently constructed with curtain walls made almost entirely of glass. Similarly, laminated glass has been widely applied to vehicles for windscreens. While glass containers have always been used for storage and are valued for their hygienic properties, glass has been utilized increasingly in industry. Optical glass for spectacles has been used since the late Middle Ages. The production of lenses has become increasingly proficient, aiding astronomers as well as having other application in medicine and science. Glass is also employed as the aperture cover in many solar energy systems.

Question: What type of power systems use glass?
Ans: solar


Article: In the last years of the nineteenth century, Planck was investigating the problem of black-body radiation first posed by Kirchhoff some forty years earlier. It is well known that hot objects glow, and that hotter objects glow brighter than cooler ones. The electromagnetic field obeys laws of motion similarly to a mass on a spring, and can come to thermal equilibrium with hot atoms. The hot object in equilibrium with light absorbs just as much light as it emits. If the object is black, meaning it absorbs all the light that hits it, then its thermal light emission is maximized.

Question: Who posed the problem of black-body radiation?
Ans: Kirchhoff


Article: Most elevators have a location in which the permit for the building owner to operate the elevator is displayed. While some jurisdictions require the permit to be displayed in the elevator cab, other jurisdictions allow for the operating permit to be kept on file elsewhere – such as the maintenance office – and to be made available for inspection on demand. In such cases instead of the permit being displayed in the elevator cab, often a notice is posted in its place informing riders of where the actual permits are kept.

Question: Aside from the elevator, where else might a permit be displayed?
Ans:
the maintenance office