1,255 accepted99% rate19.9 hours
1,255 accepted99% rate19.9 hours
In what year did Wilhelm Roentgen discover X-rays? Answer with the four-digit year only.
In what year was SpaceX founded? Answer with the four-digit year only.
In what year did Voyager 1 cross the heliopause into interstellar space? Answer with the four-digit year only.
What is the capital of Saudi Arabia? Answer with the city name only.
How many characters long is an IATA airline designator? Answer with the whole number only.
In what year did Yang Liwei become China's first astronaut in space? Answer with the four-digit year only.
In what year did Isaac Newton die? 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.
What is the capital of Cuba? Answer with the English name of the city 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.
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.
How many provinces does Canada have? Answer with the whole number 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.
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 did the Australian colonies federate into the Commonwealth of Australia? Answer with the four-digit year 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 Qatar Airways? Answer with the two-character code only.