Problem: Gramophone record:

Electrical recording preceded electrical home reproduction because of the initial high cost of the new system. In 1925, the Victor company introduced the Victor Orthophonic Victrola, an acoustical record player that was specifically designed to play electrically recorded discs, as part of a line that also included electrically reproducing Electrolas. The acoustical Orthophonics ranged in price from US$95 to US$300, depending on cabinetry; by comparison, the cheapest Electrola cost US$650, the price of a new Ford automobile in an era when clerical jobs paid about $20 a week.

What was the initial cost range of early recording devices?
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A: US$95 to US$300


Problem: 2008 Summer Olympics torch relay:

Prior to the rally, seven anti-China protestors were arrested in Hanoi after unfurling a banner and shouting "Boycott the Beijing Olympics" through a loudhailer at a market. A Vietnamese American was deported for planning protests against the torch, while a prominent blogger, Điếu Cày (real name Nguyễn Văn Hải), who blogged about protests around the world and who called for demonstrations in Vietnam, was arrested on charges of tax evasion. Outside Vietnam, there were protests by overseas Vietnamese in Paris, San Francisco and Canberra. Lê Minh Phiếu, a torchbearer who is a Vietnamese law student studying in France, wrote a letter to the president of the International Olympic Committee protesting China's "politicisation of the Olympics", citing maps of the torch relay at the official Beijing Olympic website depicting the disputed islands as Chinese territory and posted it on his blog. One day before the relay was to start, the official website appeared to have been updated to remove the disputed islands and dotted lines marking China's maritime claims in the South China Sea.

Which torchbearer sent a letter of protest to the president of the International Olympic Committee?
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A: Lê Minh Phiếu


Problem: Biodiversity:

Finally, an introduced species may unintentionally injure a species that depends on the species it replaces. In Belgium, Prunus spinosa from Eastern Europe leafs much sooner than its West European counterparts, disrupting the feeding habits of the Thecla betulae butterfly (which feeds on the leaves). Introducing new species often leaves endemic and other local species unable to compete with the exotic species and unable to survive. The exotic organisms may be predators, parasites, or may simply outcompete indigenous species for nutrients, water and light.

What types of new nutrients can be introduced?
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A: unanswerable


Problem: Time:

Time appears to have a direction—the past lies behind, fixed and immutable, while the future lies ahead and is not necessarily fixed. Yet for the most part the laws of physics do not specify an arrow of time, and allow any process to proceed both forward and in reverse. This is generally a consequence of time being modeled by a parameter in the system being analyzed, where there is no "proper time": the direction of the arrow of time is sometimes arbitrary. Examples of this include the Second law of thermodynamics, which states that entropy must increase over time (see Entropy); the cosmological arrow of time, which points away from the Big Bang, CPT symmetry, and the radiative arrow of time, caused by light only traveling forwards in time (see light cone). In particle physics, the violation of CP symmetry implies that there should be a small counterbalancing time asymmetry to preserve CPT symmetry as stated above. The standard description of measurement in quantum mechanics is also time asymmetric (see Measurement in quantum mechanics).

Which law states that entropy must increase in the past?
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A:
unanswerable