The MP3 lossy audio data compression algorithm takes advantage of a perceptual limitation of human hearing called auditory masking. In 1894, the American physicist Alfred M. Mayer reported that a tone could be rendered inaudible by another tone of lower frequency. In 1959, Richard Ehmer described a complete set of auditory curves regarding this phenomenon. Ernst Terhardt et al. created an algorithm describing auditory masking with high accuracy. This work added to a variety of reports from authors dating back to Fletcher, and to the work that initially determined critical ratios and critical bandwidths.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What is the limitation in human hearing referred to as?
Ah, so.. auditory masking

The apparently sudden appearance of nearly modern flowers in the fossil record initially posed such a problem for the theory of evolution that it was called an "abominable mystery" by Charles Darwin. However, the fossil record has considerably grown since the time of Darwin, and recently discovered angiosperm fossils such as Archaefructus, along with further discoveries of fossil gymnosperms, suggest how angiosperm characteristics may have been acquired in a series of steps. Several groups of extinct gymnosperms, in particular seed ferns, have been proposed as the ancestors of flowering plants, but there is no continuous fossil evidence showing exactly how flowers evolved. Some older fossils, such as the upper Triassic Sanmiguelia, have been suggested. Based on current evidence, some propose that the ancestors of the angiosperms diverged from an unknown group of gymnosperms in the Triassic period (245202 million years ago). Fossil angiosperm-like pollen from the Middle Triassic (247.2242.0 Ma) suggests an older date for their origin. A close relationship between angiosperms and gnetophytes, proposed on the basis of morphological evidence, has more recently been disputed on the basis of molecular evidence that suggest gnetophytes are instead more closely related to other gymnosperms.[citation needed]
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Why has the relationship between gnetophytes and gymnosperms been disputed?
Ah, so.. unanswerable

The securitization markets supported by the shadow banking system started to close down in the spring of 2007 and nearly shut-down in the fall of 2008. More than a third of the private credit markets thus became unavailable as a source of funds. According to the Brookings Institution, the traditional banking system does not have the capital to close this gap as of June 2009: "It would take a number of years of strong profits to generate sufficient capital to support that additional lending volume." The authors also indicate that some forms of securitization are "likely to vanish forever, having been an artifact of excessively loose credit conditions."
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): How much of the private credit markets become unavailable as a source of funds?
Ah, so..
More than a third