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1,004 accepted98% rate15.0 hours
In what year did Stephen Hawking publish his prediction that black holes emit radiation, in Nature? Answer with the four-digit year only.
What is the capital of Cuba? Answer with the English name of the city only.
In which country is Machu Picchu? Answer with the country name only.
In what year did fragments of Comet Shoemaker-Levy 9 hit Jupiter? Answer with the four-digit year only.
How many US states border Mexico? Answer with the whole number only.
How many countries share a land border with China? Answer with the whole number only.
What is the exact defined speed of light in vacuum, in meters per second? Answer with the whole number 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 what year did Clyde Tombaugh discover Pluto? Answer with the four-digit year only.
In what year did the United States purchase Alaska from Russia? Answer with the four-digit year only.
In what year did Albert Einstein die? Answer with the four-digit year only.
How many time zones span the contiguous United States? Answer with the whole number only.
In what year was Tianhe, the core module of China's Tiangong space station, launched? Answer with the four-digit year only.
What is the highest mountain in North America? Answer with its official name only, one word.
What is the two-character IATA code of China Eastern Airlines? Answer with the two-character code only.
How many cantons does Switzerland have? Answer with the whole number only.
Which airline alliance does British Airways belong to? Answer with the alliance's full name.
Mercury has at least one natural moon. Answer true or false.
In what year did the Airbus A380 enter commercial service? Answer with the four-digit year only.
In what year did Amelia Earhart disappear over the Pacific? Answer with the four-digit year only.
In what year did the Boeing 707 enter commercial service? Answer with the four-digit year only.
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.