The problem: Answer a question about this article:
The modern Slavic peoples carry a variety of mitochondrial DNA haplogroups and Y-chromosome DNA haplogroups. Yet two paternal haplogroups predominate: R1a1a [M17] and I2a2a [L69.2=T/S163.2]. The frequency of Haplogroup R1a ranges from 63.39% in the Sorbs, through 56.4% in Poland, 54% in Ukraine, 52% in Russia, Belarus, to 15.2% in Republic of Macedonia, 14.7% in Bulgaria and 12.1% in Herzegovina. The correlation between R1a1a [M17] and the speakers of Indo-European languages, particularly those of Eastern Europe (Russian) and Central and Southern Asia, was noticed in the late 1990s. From this Spencer Wells and colleagues, following the Kurgan hypothesis, deduced that R1a1a arose on the Pontic-Caspian steppe.
What is the frequency of Haplogroup R1a in Russia?
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The answer: 52%

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From the 1950s on, many areas of the Great Plains have become productive crop-growing areas because of extensive irrigation on large landholdings. The United States is a major exporter of agricultural products. The southern portion of the Great Plains lies over the Ogallala Aquifer, a huge underground layer of water-bearing strata dating from the last ice age. Center pivot irrigation is used extensively in drier sections of the Great Plains, resulting in aquifer depletion at a rate that is greater than the ground's ability to recharge.
what type of irrigation is used in the great plains?
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The answer: Center pivot irrigation

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Cyprus suffers from a chronic shortage of water. The country relies heavily on rain to provide household water, but in the past 30 years average yearly precipitation has decreased. Between 2001 and 2004, exceptionally heavy annual rainfall pushed water reserves up, with supply exceeding demand, allowing total storage in the island's reservoirs to rise to an all-time high by the start of 2005. However, since then demand has increased annually a result of local population growth, foreigners moving to Cyprus and the number of visiting tourists while supply has fallen as a result of more frequent droughts.
When did Cyprus receive enough rainfall to fill up their water reserves?
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The answer: Between 2001 and 2004

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The design architecture of USB is asymmetrical in its topology, consisting of a host, a multitude of downstream USB ports, and multiple peripheral devices connected in a tiered-star topology. Additional USB hubs may be included in the tiers, allowing branching into a tree structure with up to five tier levels. A USB host may implement multiple host controllers and each host controller may provide one or more USB ports. Up to 127 devices, including hub devices if present, may be connected to a single host controller. USB devices are linked in series through hubs. One hubbuilt into the host controlleris the root hub.
The design of USB is asymmetrical in what?
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The answer:
its topology