The invention of compass provided conditions for____.
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Wood block printing was invented in ____and began to be widely used in ____.
FAST (Five-hundred-meter Aperture Spherical Telescope ) Tianyan was proposed by Chinese astronomer ____in ____and was completed in ____years.
Human space activities mainly include three major areas: ____, manned spaceflight and ____.
In ____, the earliest extant was printed. A. 868A.D.B. 1150A.D.C. 612A.D.D. 121A.D.