In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
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Question: How was access gained to Alaska, 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, 5017,000 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.

Answer: the land bridge

Question: What does Thapar decry as helping to put too much focus on certain aspects of Indian history?, Context: Romila Thapar notes that the division into Hindu-Muslim-British periods of Indian history gives too much weight to "ruling dynasties and foreign invasions", neglecting the social-economic history which often showed a strong continuity. The division into Ancient-Medieval-Modern periods overlooks the fact that the Muslim conquests occurred gradually during which time many things came and went off, while the south was never completely conquered. According to Thapar, a periodisation could also be based on "significant social and economic changes", which are not strictly related to a change of ruling powers.[note 1]

Answer: division into Hindu-Muslim-British periods

Question: Which of the following is NOT a goal of phorphor LED development: higher light output, optical losses, or higher operation temperatures?, Context: Among the challenges being faced to improve the efficiency of LED-based white light sources is the development of more efficient phosphors. As of 2010, the most efficient yellow phosphor is still the YAG phosphor, with less than 10% Stoke shift loss. Losses attributable to internal optical losses due to re-absorption in the LED chip and in the LED packaging itself account typically for another 10% to 30% of efficiency loss. Currently, in the area of phosphor LED development, much effort is being spent on optimizing these devices to higher light output and higher operation temperatures. For instance, the efficiency can be raised by adapting better package design or by using a more suitable type of phosphor. Conformal coating process is frequently used to address the issue of varying phosphor thickness.

Answer:
optical losses