Problem: The phonograph disc record was the primary medium used for music reproduction until late in the 20th century, replacing the phonograph cylinder recordwith which it had co-existed from the late 1880s through to the 1920sby the late 1920s. Records retained the largest market share even when new formats such as compact cassette were mass-marketed. By the late 1980s, digital media, in the form of the compact disc, had gained a larger market share, and the vinyl record left the mainstream in 1991. From the 1990s to the 2010s, records continued to be manufactured and sold on a much smaller scale, and were especially used by disc jockeys (DJ)s, released by artists in some genres, and listened to by a niche market of audiophiles. The phonograph record has made a niche resurgence in the early 21st century 9.2 million records were sold in the U.S. in 2014, a 260% increase since 2009. Likewise, in the UK sales have increased five-fold from 2009 to 2014.
From the 1990s to 2010s who was the primary consumer of vinyl records?
The answer is the following: disc jockeys (DJ)s

Problem: The Swingle Singers used nonsense words to sound like instruments, but have been known to produce non-verbal versions of musical instruments. Like the other groups, examples of their music can be found on YouTube. Beatboxing, more accurately known as vocal percussion, is a technique used in a cappella music popularized by the hip-hop community, where rap is often performed a cappella also. The advent of vocal percussion added new dimensions to the a cappella genre and has become very prevalent in modern arrangements. Petra Haden used a four-track recorder to produce an a cappella version of The Who Sell Out including the instruments and fake advertisements on her album Petra Haden Sings: The Who Sell Out in 2005. Haden has also released a cappella versions of Journey's "Don't Stop Believin'", The Beach Boys' "God Only Knows" and Michael Jackson's "Thriller". In 2009, Toyota commissioned Haden to perform three songs for television commercials for the third-generation Toyota Prius, including an a cappella version of The Bellamy Brothers' 1970s song "Let Your Love Flow".[citation needed]
What car manufacturer hired Petra Haden to perform a capella songs in commercials for their car?
The answer is the following: Toyota

Problem: Because the electron mobility is higher than the hole mobility for all semiconductor materials, a given bipolar npn transistor tends to be swifter than an equivalent pnp transistor. GaAs has the highest electron mobility of the three semiconductors. It is for this reason that GaAs is used in high-frequency applications. A relatively recent FET development, the high-electron-mobility transistor (HEMT), has a heterostructure (junction between different semiconductor materials) of aluminium gallium arsenide (AlGaAs)-gallium arsenide (GaAs) which has twice the electron mobility of a GaAs-metal barrier junction. Because of their high speed and low noise, HEMTs are used in satellite receivers working at frequencies around 12 GHz. HEMTs based on gallium nitride and aluminium gallium nitride (AlGaN/GaN HEMTs) provide a still higher electron mobility and are being developed for various applications.
What is quicker, a bipolar n-p-n transistor or a p-n-p transistor?
The answer is the following: a given bipolar npn transistor

Problem: In the wake of the racially-motivated" church shooting in Charleston, South Carolina, Yale was under criticism again in the summer of 2015 for Calhoun College, one of 12 residential colleges, which was named after John C. Calhoun, a slave-owner and strong slavery supporter in the nineteenth century. In July 2015 students signed a petition calling for the name change. They argued in the petition thatwhile Calhoun was respected in the 19th century as an "extraordinary American statesman"he was "one of the most prolific defenders of slavery and white supremacy" in the history of the United States. In August 2015 Yale President Peter Salovey addressed the Freshman Class of 2019 in which he responded to the racial tensions but explained why the college would not be renamed. He described Calhoun as a "a notable political theorist, a vice president to two different U.S. presidents, a secretary of war and of state, and a congressman and senator representing South Carolina." He acknowledged that Calhoun also "believed that the highest forms of civilization depend on involuntary servitude. Not only that, but he also believed that the races he thought to be inferior, black people in particular, ought to be subjected to it for the sake of their own best interests." Racial tensions increased in the fall of 2015 centering on comments by Nicholas A. Christakis and his wife Erika regarding freedom of speech. In April 2016 Salovey announced that "despite decades of vigorous alumni and student protests," Calhoun's name will remain on the Yale residential college explaining that it is preferable for Yale students to live in Calhoun's "shadow" so they will be "better prepared to rise to the challenges of the present and the future." He claimed that if they removed Calhoun's name, it would "obscure" his "legacy of slavery rather than addressing it." "Yale is part of that history" and "We cannot erase American history, but we can confront it, teach it and learn from it." One change that will be issued is the title of "master" for faculty members who serve as residential college leaders will be renamed to "head of college" due to its connotation of slavery.
Whose comments increased racial tension in the Fall of 2015?
The answer is the following:
Nicholas A. Christakis and his wife Erika