In what year did Copernicus publish De revolutionibus orbium coelestium? Answer with the four-digit year only.
In what year did Stephen Hawking publish his prediction that black holes emit radiation, in Nature? Answer with the four-digit year only.
In what year did fragments of Comet Shoemaker-Levy 9 hit Jupiter? Answer with the four-digit year only.
How many countries share a land border with China? Answer with the whole number only.
In what year did the Chelyabinsk meteor explode over Russia? Answer with the four-digit year only.
What is the two-character IATA code of KLM? Answer with the two-character code only.
What is the IATA code of Paris Charles de Gaulle Airport? Answer with the three-letter code only.
How many engines did the McDonnell Douglas DC-10 have? Answer with the whole number only.
In what year did Clyde Tombaugh discover Pluto? Answer with the four-digit year only.
What is the flag carrier airline of the Netherlands? Answer with the airline name only.
In what year did Theodore Maiman demonstrate the first working laser? Answer with the four-digit year only.
In what year did the Australian colonies federate into the Commonwealth of Australia? Answer with the four-digit year only.
How many time zones span the contiguous United States? Answer with the whole number only.
Which airline alliance does British Airways belong to? Answer with the alliance's full name.
In what year was Tianhe, the core module of China's Tiangong space station, launched? Answer with the four-digit year only.
Who led the team that built Chicago Pile-1, the first nuclear reactor? Answer with the surname only.
In what year did Hayabusa2 return its asteroid Ryugu samples to Earth? Answer with the four-digit year only.
What is the two-character IATA code of Qatar Airways? Answer with the two-character code only.
