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 Paul Dirac publish his relativistic equation for the electron? Answer with the four-digit year only.
In what year did Alaska Air Group complete its acquisition of Hawaiian Airlines? 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.
In what year did Niels Bohr publish his model of the hydrogen atom? Answer with the four-digit year only.
In which country is the temple complex of Angkor Wat? Answer with the country name only.
Which US airline did Herb Kelleher co-found? Answer with the one-word name only, without the word Airlines.
In what year did the United States purchase Alaska from Russia? Answer with the four-digit year only.
What is the highest mountain in North America? Answer with its official name only, one word.
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 did the travel group Thomas Cook and its airline collapse? Answer with the four-digit year only.
What is the two-character IATA code of Qatar Airways? Answer with the two-character code only.
Mercury has at least one natural moon. Answer true or false.
In what year did Amelia Earhart disappear over the Pacific? Answer with the four-digit year only.
The Moon has a thick atmosphere. Answer true or false.
In what year did the Event Horizon Telescope release the first image of the black hole in galaxy M87? Answer with the four-digit year only.
Which planet is closest to the Sun? Answer with the name only.
