Problem: Lighting:

The small, head-mounted device measures an individual's daily rest and activity patterns, as well as exposure to short-wavelength light that stimulates the circadian system. The device measures activity and light together at regular time intervals and electronically stores and logs its operating temperature. The Daysimeter can gather data for up to 30 days for analysis.

What type of light stimulates the circadian system?
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A: short-wavelength light

Problem: Utrecht:

Utrecht is well-connected to the Dutch road network. Two of the most important major roads serve the city of Utrecht: the A12 and A2 motorways connect Amsterdam, Arnhem, The Hague and Maastricht, as well as Belgium and Germany. Other major motorways in the area are the AlmereBreda A27 and the UtrechtGroningen A28. Due to the increasing traffic and the ancient city plan, traffic congestion is a common phenomenon in and around Utrecht, causing elevated levels of air pollutants. This has led to a passionate debate in the city about the best way to improve the city's air quality.

What does traffic elevate
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A: increasing traffic and the ancient city plan, traffic congestion is a common phenomenon in and around Utrecht, causing elevated levels of air pollutants

Problem: Samurai:

A samurai could take concubines but their backgrounds were checked by higher-ranked samurai. In many cases, taking a concubine was akin to a marriage. Kidnapping a concubine, although common in fiction, would have been shameful, if not criminal. If the concubine was a commoner, a messenger was sent with betrothal money or a note for exemption of tax to ask for her parents' acceptance. Even though the woman would not be a legal wife, a situation normally considered a demotion, many wealthy merchants believed that being the concubine of a samurai was superior to being the legal wife of a commoner. When a merchant's daughter married a samurai, her family's money erased the samurai's debts, and the samurai's social status improved the standing of the merchant family. If a samurai's commoner concubine gave birth to a son, the son could inherit his father's social status.

Why did merchants prefer that their daughters not marry samurai?
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A: her family's money erased the samurai's debts

Problem: YouTube:

YouTube relies on its users to flag the content of videos as inappropriate, and a YouTube employee will view a flagged video to determine whether it violates the site's terms of service. In July 2008, the Culture and Media Committee of the House of Commons of the United Kingdom stated that it was "unimpressed" with YouTube's system for policing its videos, and argued that "proactive review of content should be standard practice for sites hosting user-generated content". YouTube responded by stating:

What do uses rely on YouTube to flag?
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A:
unanswerable