Problem: Several hundred pro-Tibet protesters gathered at the Trocadéro with banners and Tibetan flags, and remained there for a peaceful protest, never approaching the torch relay itself. Among them was Jane Birkin, who spoke to the media about the "lack of freedom of speech" in China. Also present was Thupten Gyatso, President of the French Tibetan community, who called upon pro-Tibet demonstrators to "remain calm, non-violent, peaceful".
Who, of the Trocadéro protest, spoke to the media?
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Answer: Jane Birkin


Problem: Because the electron mobility is higher than the hole mobility for all semiconductor materials, a given bipolar n–p–n transistor tends to be swifter than an equivalent p–n–p 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 semiconductor has the highest electron mobility?
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Answer: GaAs


Problem: In 1901, 10-inch disc records were introduced, followed in 1903 by 12-inch records. These could play for more than three and four minutes respectively, while contemporary cylinders could only play for about two minutes. In an attempt to head off the disc advantage, Edison introduced the Amberol cylinder in 1909, with a maximum playing time of 4½ minutes (at 160 rpm), which in turn were superseded by Blue Amberol Records, which had a playing surface made of celluloid, a plastic, which was far less fragile. Despite these improvements, during the 1910s discs decisively won this early format war, although Edison continued to produce new Blue Amberol cylinders for an ever-dwindling customer base until late in 1929. By 1919 the basic patents for the manufacture of lateral-cut disc records had expired, opening the field for countless companies to produce them. Analog disc records would dominate the home entertainment market until they were outsold by the digital compact disc in the late 1980s (which was in turn supplanted by digital audio recordings distributed via online music stores and Internet file sharing).
What disc format was the least fragile prior to 1919?
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Answer:
Amberol cylinder