Question: In the late 1980s, key breakthroughs in GaN epitaxial growth and p-type doping ushered in the modern era of GaN-based optoelectronic devices. Building upon this foundation, Dr. Moustakas at Boston University patented a method for producing high-brightness blue LEDs using a new two-step process. Two years later, in 1993, high-brightness blue LEDs were demonstrated again by Shuji Nakamura of Nichia Corporation using a gallium nitride growth process similar to Dr. Moustakas's. Both Dr. Moustakas and Mr. Nakamura were issued separate patents, which confused the issue of who was the original inventor (partly because although Dr. Moustakas invented his first, Dr. Nakamura filed first).[citation needed] This new development revolutionized LED lighting, making high-power blue light sources practical, leading to the development of technologies like BlueRay, as well as allowing the bright high resolution screens of modern tablets and phones.[citation needed]
Is there an answer to this question: What technology was made possible by low-power blue light sources?

Answer: unanswerable

Question: Some of Chopin's well-known pieces have acquired descriptive titles, such as the Revolutionary Etude (Op. 10, No. 12), and the Minute Waltz (Op. 64, No. 1). However, with the exception of his Funeral March, the composer never named an instrumental work beyond genre and number, leaving all potential extramusical associations to the listener; the names by which many of his pieces are known were invented by others. There is no evidence to suggest that the Revolutionary Etude was written with the failed Polish uprising against Russia in mind; it merely appeared at that time. The Funeral March, the third movement of his Sonata No. 2 (Op. 35), the one case where he did give a title, was written before the rest of the sonata, but no specific event or death is known to have inspired it.
Is there an answer to this question: How many instrumental works did Chopin give a descriptive name to?

Answer: one

Question: Melbourne is typical of Australian capital cities in that after the turn of the 20th century, it expanded with the underlying notion of a 'quarter acre home and garden' for every family, often referred to locally as the Australian Dream. This, coupled with the popularity of the private automobile after 1945, led to the auto-centric urban structure now present today in the middle and outer suburbs. Much of metropolitan Melbourne is accordingly characterised by low density sprawl, whilst its inner city areas feature predominantly medium-density, transit-oriented urban forms. The city centre, Docklands, St. Kilda Road and Southbank areas feature high-density forms.
Is there an answer to this question: Do the Docklands, St. Kilda Road, and Southbank areas feature high-density or low-density forms?

Answer: high-density

Question: Valleys and plains are found along the coastline and rivers. The north of the province lies just south of the Yangtze Delta, and consists of plains around the cities of Hangzhou, Jiaxing, and Huzhou, where the Grand Canal of China enters from the northern border to end at Hangzhou. Another relatively flat area is found along the Qu River around the cities of Quzhou and Jinhua. Major rivers include the Qiangtang and Ou Rivers. Most rivers carve out valleys in the highlands, with plenty of rapids and other features associated with such topography. Well-known lakes include the West Lake of Hangzhou and the South Lake of Jiaxing.
Is there an answer to this question: What is not a well-known lake of Jiaxing?

Answer:
unanswerable