Information: - The Czech Republic, also known by the short name Czechia, is a nation state in Central Europe bordered by Germany to the west, Austria to the south, Slovakia to the east and Poland to the northeast. The Czech Republic covers an area of with mostly temperate continental climate and oceanic climate. It is a unitary parliamentary republic, has 10.5million inhabitants and the capital and largest city is Prague, with over 1.2million residents. The Czech Republic includes the historical territories of Bohemia, Moravia, and Czech Silesia. - Czechoslovakia or Czecho-Slovakia (Czech and , "esko-Slovensko") was a sovereign state in Central Europe that existed from October 1918, when it declared its independence from the Austro-Hungarian Empire, until its peaceful dissolution into the Czech Republic and Slovakia on 1 January 1993. - The Czech Air Force (Czech: "Vzdusne sily Armady eske republiky", literally the "Air Force of the Army of the Czech Republic"), is the air force branch of the Army of the Czech Republic. Along with the Land Forces, the Air Force is the major Czech military force. Former Joint Forces Command and Support Forces Command HQs were disbanded by 30 June 2013. The Czech Air Force succeeded the Czechoslovak Air Force together with the Slovak Air Force in 1993. - Slovakia, officially the Slovak Republic, is a landlocked country in Central Europe. It is bordered by the Czech Republic and Austria to the west, Poland to the north, Ukraine to the east and Hungary to the south. Slovakia's territory spans about and is mostly mountainous. The population is over 5 million and comprises mostly ethnic Slovaks. The capital and largest city is Bratislava. The official language is Slovak, a member of the Slavic language family. - The Czechoslovak Air Force ("eskoslovenske vojenske letectvo") was the air force branch of the military of Czechoslovakia. It was known as the Czechoslovak Army Air Force ("eskoslovenske letectvo") from 1918 to 1939. In 1993, it was divided into the Czech Air Force and the Slovak Air Force. - The Slovak Air Force, known since 2002 as the Air Force of the Armed Forces of the Slovak Republic, is the aviation and air defense branch of the Slovak Armed Forces. It operates 25 aircraft and 9 helicopters from 3 air bases: Malacky Air Base, Sliac Air Base, Presov Air Base. Together with the Czech Air Force, it succeeded the Czechoslovak Air Force in 1993. The Slovak Air Force is part of the NATO Integrated Air and Missiles Defense System NATINADS. - The Aero A.20 was a biplane fighter aircraft built in Czechoslovakia in 1923 . It was evaluated for Czechoslovak Air Force service against Aero 's competing A.18 and A.19 designs , a competition that the A.18 won , meaning that this aircraft never entered production , and only a single prototype was ever built . What is the relationship between 'aero a.20' and 'czech air force'?
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