Problem: Air defence in naval tactics, especially within a carrier group, is often built around a system of concentric layers with the aircraft carrier at the centre. The outer layer will usually be provided by the carrier's aircraft, specifically its AEW&C aircraft combined with the CAP. If an attacker is able to penetrate this layer, then the next layers would come from the surface-to-air missiles carried by the carrier's escorts; the area-defence missiles, such as the RIM-67 Standard, with a range of up to 100 nmi, and the point-defence missiles, like the RIM-162 ESSM, with a range of up to 30 nmi. Finally, virtually every modern warship will be fitted with small-calibre guns, including a CIWS, which is usually a radar-controlled Gatling gun of between 20mm and 30mm calibre capable of firing several thousand rounds per minute.
Air defence in such places as a carrier group are built around what?
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Answer: a system of concentric layers


Problem: King Matthias Corvinus of Hungary (1458–1490) was one of the most prominent figures of the period, directing campaigns to the West, conquering Bohemia in answer to the Pope's call for help against the Hussite Protestants. Also, in resolving political hostilities with the German emperor Frederick III of Habsburg, he invaded his western domains. Matthew organized the Black Army of mercenary soldiers; it was considered as the biggest army of its time. Using this powerful tool, the Hungarian king led wars against the Turkish armies and stopped the Ottomans during his reign. After the death of Matthew, and with end of the Black Army, the Ottoman Empire grew in strength and Central Europe was defenseless. At the Battle of Mohács, the forces of the Ottoman Empire annihilated the Hungarian army and Louis II of Hungary drowned in the Csele Creek while trying to escape. The leader of the Hungarian army, Pál Tomori, also died in the battle. This is considered to be one of the final battles of Medieval times.
Who did Matthias defeat to conquer Bohemia?
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Answer: Hussite Protestants


Problem: The evolution of Proto-Greek should be considered within the context of an early Paleo-Balkan sprachbund that makes it difficult to delineate exact boundaries between individual languages. The characteristically Greek representation of word-initial laryngeals by prothetic vowels is shared, for one, by the Armenian language, which also seems to share some other phonological and morphological peculiarities of Greek; this has led some linguists to propose a hypothetical closer relationship between Greek and Armenian, although evidence remains scant.
What progression coincided with the the early Greek states that makes it difficult to give credit for the language and differences ? 
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Answer:
Paleo-Balkan sprachbund that makes it difficult to delineate exact boundaries between individual languages.