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You answered "Its diameter is 150k light years". Click "CONTINUE" to proceed to the next question.
Interesting fact:
At the end of the 19th century, x-rays revolutionised medicine. Initially deemed harmless, non-medical x-.ray photography became quite the fad. Once it was discovered that they cause cancer, that fad quickly faded. But x-rays can also cure it: in cancer radiotherapy, x-rays are sometimes used to burn away tumors.