Koom nrog Z Zej Zog - tau txais cov xwm txheej caw, tshaj tawm, Lub Limtiam Digest, thiab lub sijhawm los koom nrog.
The astronomer, science communicator, thinker, writer, and teacher Carl Sagan (1934–1996) had an influence as a scientist that is almost unimaginable today.…