Problem: Pitch (music):

For example, one might refer to the A above middle C as a', A4, or 440 Hz. In standard Western equal temperament, the notion of pitch is insensitive to "spelling": the description "G4 double sharp" refers to the same pitch as A4; in other temperaments, these may be distinct pitches. Human perception of musical intervals is approximately logarithmic with respect to fundamental frequency: the perceived interval between the pitches "A220" and "A440" is the same as the perceived interval between the pitches A440 and A880. Motivated by this logarithmic perception, music theorists sometimes represent pitches using a numerical scale based on the logarithm of fundamental frequency. For example, one can adopt the widely used MIDI standard to map fundamental frequency, f, to a real number, p, as follows

Human perception of musical intervals is approximately what?
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A: logarithmic


Problem: United States Air Force:

The service's B-2A aircraft entered service in the 1990s, its B-1B aircraft in the 1980s and its current B-52H aircraft in the early 1960s. The B-52 Stratofortress airframe design is over 60 years old and the B-52H aircraft currently in the active inventory were all built between 1960 and 1962. The B-52H is scheduled to remain in service for another 30 years, which would keep the airframe in service for nearly 90 years, an unprecedented length of service for any aircraft. The B-21 is projected to replace the B-52 and parts of the B-1B force by the mid-2020s.

What aircraft in the USAF was introduced in the 1960s?
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A: B-52H


Problem: Child labour:

Out of former Soviet Union republics Uzbekistan continued and expanded the program of child labour on industrial scale to increase profits on the main source of Islam Karimov's income, cotton harvesting. In September, when school normally starts, the classes are suspended and children are sent to cotton fields for work, where they are assigned daily quotas of 20 to 60 kg of raw cotton they have to collect. This process is repeated in spring, when collected cotton needs to be hoed and weeded. In 2006 it is estimated that 2.7 million children were forced to work this way.

Did they have daily quotas for cotton?
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A: daily quotas of 20 to 60 kg of raw cotton


Problem: Detroit:

Detroit (/dᵻˈtrɔɪt/) is the most populous city in the U.S. state of Michigan, the fourth-largest city in the Midwest and the largest city on the United States–Canada border. It is the seat of Wayne County, the most populous county in the state. Detroit's metropolitan area, known as Metro Detroit, is home to 5.3 million people, making it the fourteenth-most populous metropolitan area in the United States and the second-largest in the Midwestern United States (behind Chicago). It is a major port on the Detroit River, a strait that connects the Great Lakes system to the Saint Lawrence Seaway. The City of Detroit anchors the second-largest economic region in the Midwest, behind Chicago, and the thirteenth-largest in the United States.

In what region of the country is Detroit located?
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A:
Midwest