Q: Extract the answer to the question from the following context. Question: West North America had a group of? Context: The specifics of Paleo-Indian migration to and throughout the Americas, including the exact dates and routes traveled, provide the subject of ongoing research and discussion. According to archaeological and genetic evidence, North and South America were the last continents in the world with human habitation. During the Wisconsin glaciation, 50–17,000 years ago, falling sea levels allowed people to move across the land bridge of Beringia that joined Siberia to north west North America (Alaska). Alaska was a glacial refugia because it had low snowfall, allowing a small population to exist. The Laurentide Ice Sheet covered most of North America, blocking nomadic inhabitants and confining them to Alaska (East Beringia) for thousands of years.
A: nomadic inhabitants

Q: Extract the answer to the question from the following context. Question: What did al-Haytham's work result in? Context: In the early 11th century, the Muslim physicist Ibn al-Haytham (Alhacen or Alhazen) discussed space perception and its epistemological implications in his Book of Optics (1021), he also rejected Aristotle's definition of topos (Physics IV) by way of geometric demonstrations and defined place as a mathematical spatial extension. His experimental proof of the intromission model of vision led to changes in the understanding of the visual perception of space, contrary to the previous emission theory of vision supported by Euclid and Ptolemy. In "tying the visual perception of space to prior bodily experience, Alhacen unequivocally rejected the intuitiveness of spatial perception and, therefore, the autonomy of vision. Without tangible notions of distance and size for correlation, sight can tell us next to nothing about such things."
A: changes in the understanding of the visual perception of space

Q: Extract the answer to the question from the following context. Question: What year was the peak of the public transportation system? Context: Melbourne has an integrated public transport system based around extensive train, tram, bus and taxi systems. Flinders Street Station was the world's busiest passenger station in 1927 and Melbourne's tram network overtook Sydney's to become the world's largest in the 1940s, at which time 25% of travellers used public transport but by 2003 it had declined to just 7.6%. The public transport system was privatised in 1999, symbolising the peak of the decline. Despite privatisation and successive governments persisting with auto-centric urban development into the 21st century, there have since been large increases in public transport patronage, with the mode share for commuters increasing to 14.8% and 8.4% of all trips. A target of 20% public transport mode share for Melbourne by 2020 was set by the state government in 2006. Since 2006 public transport patronage has grown by over 20%.
A: 1940s

Q: Extract the answer to the question from the following context. Question: The Three Jewels are also called what? Context: Buddhist schools vary on the exact nature of the path to liberation, the importance and canonicity of various teachings and scriptures, and especially their respective practices. Buddhism denies a creator deity and posits that mundane deities such as Mahabrahma are misperceived to be a creator. The foundations of Buddhist tradition and practice are the Three Jewels: the Buddha, the Dharma (the teachings), and the Sangha (the community). Taking "refuge in the triple gem" has traditionally been a declaration and commitment to being on the Buddhist path, and in general distinguishes a Buddhist from a non-Buddhist. Other practices are Ten Meritorious Deeds including, giving charity to reduce the greediness; following ethical precepts; renouncing conventional living and becoming a monastic; the development of mindfulness and practice of meditation; cultivation of higher wisdom and discernment; study of scriptures; devotional practices; ceremonies; and in the Mahayana tradition, invocation of buddhas and bodhisattvas.
A:
the triple gem