Problem: Railway electrification system:

Motors have very little room for electrical insulation so they generally have low voltage ratings. Because transformers (prior to the development of power electronics) cannot step down DC voltages, trains were supplied with a relatively low DC voltage that the motors can use directly. The most common DC voltages are listed in the previous section. Third (and fourth) rail systems almost always use voltages below 1 kV for safety reasons while overhead wires usually use higher voltages for efficiency. ("Low" voltage is relative; even 600 V can be instantly lethal when touched.)

Which system uses higher voltages?
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A: overhead wires

Problem: Glass:

Although the atomic structure of glass shares characteristics of the structure in a supercooled liquid, glass tends to behave as a solid below its glass transition temperature. A supercooled liquid behaves as a liquid, but it is below the freezing point of the material, and in some cases will crystallize almost instantly if a crystal is added as a core. The change in heat capacity at a glass transition and a melting transition of comparable materials are typically of the same order of magnitude, indicating that the change in active degrees of freedom is comparable as well. Both in a glass and in a crystal it is mostly only the vibrational degrees of freedom that remain active, whereas rotational and translational motion is arrested. This helps to explain why both crystalline and non-crystalline solids exhibit rigidity on most experimental time scales.

Despite its atomic structure, cooled glass acts like what?
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A: a solid

Problem: Asthma:

Other supportive evidence includes: a 20% difference in peak expiratory flow rate on at least three days in a week for at least two weeks, a 20% improvement of peak flow following treatment with either salbutamol, inhaled corticosteroids or prednisone, or a 20% decrease in peak flow following exposure to a trigger. Testing peak expiratory flow is more variable than spirometry, however, and thus not recommended for routine diagnosis. It may be useful for daily self-monitoring in those with moderate to severe disease and for checking the effectiveness of new medications. It may also be helpful in guiding treatment in those with acute exacerbations.

What is the rate that is used in most of the evidence?
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A: 20%

Problem: Gymnastics:

According to FIG rules, only women compete in rhythmic gymnastics. This is a sport that combines elements of ballet, gymnastics, dance, and apparatus manipulation. The sport involves the performance of five separate routines with the use of five apparatus; ball, ribbon, hoop, clubs, ropeon a floor area, with a much greater emphasis on the aesthetic rather than the acrobatic. There are also group routines consisting of 5 gymnasts and 5 apparatuses of their choice. Rhythmic routines are scored out of a possible 30 points; the score for artistry (choreography and music) is averaged with the score for difficulty of the moves and then added to the score for execution.

How many points do gymnasts need to get to the second round?
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A:
unanswerable