Hunter-gatherer societies manifest significant variability, depending on climate zone/life zone, available technology and societal structure. Archaeologists examine hunter-gatherer tool kits to measure variability across different groups. Collard et al. (2005) found temperature to be the only statistically significant factor to impact hunter-gatherer tool kits. Using temperature as a proxy for risk, Collard et al.'s results suggest that environments with extreme temperatures pose a threat to hunter-gatherer systems significant enough to warrant increased variability of tools. These results support Torrence's (1989) theory that risk of failure is indeed the most important factor in determining the structure of hunter-gatherer toolkits.
What is the threat that extreme temperature causes in environment?
significant

Seattle's foreign-born population grew 40% between the 1990 and 2000 censuses. The Chinese population in the Seattle area has origins in mainland China, Hong Kong, Southeast Asia, and Taiwan. The earliest Chinese-Americans that came in the late 19th and early 20th centuries were almost entirely from Guangdong province. The Seattle area is also home to a large Vietnamese population of more than 55,000 residents, as well as over 30,000 Somali immigrants. The Seattle-Tacoma area is also home to one of the largest Cambodian communities in the United States, numbering about 19,000 Cambodian Americans, and one of the largest Samoan communities in the mainland U.S., with over 15,000 people having Samoan ancestry. Additionally, the Seattle area had the highest percentage of self-identified mixed-race people of any large metropolitan area in the United States, according to the 2000 United States Census Bureau. According to a 2012 HistoryLink study, Seattle's 98118 ZIP code (in the Columbia City neighborhood) was one of the most diverse ZIP Code Tabulation Areas in the United States.
How many Vietnamese residents are there in Seattle? 
55,000

In mid-2015, a new model of the iPod Touch was announced by Apple, and was officially released on the Apple store on July 15, 2015. The sixth generation iPod Touch includes a wide variety of spec improvements such as the upgraded A8 processor and higher-quality screen. The core is over 5 times faster than previous models and is built to be roughly on par with the iPhone 5S. It is available in 5 different colors: Space grey, pink, gold, silver and Product (red).
What's the most recent generation of iPod Touch?
sixth