Info：Discovery Channel is an American basic cable and satellite television channel that is the flagship television property of Discovery Communications, a publicly traded company run by CEO David Zaslav. As of June 2012, Discovery Channel is the third most widely distributed cable channel in the United States, behind TBS and The Weather Channel.
Info：National Geographic Channel (also commercially abbreviated and trademarked as Nat Geo) is the American digital cable and satellite television channel that is owned by Fox Cable Networks division of 21st Century Fox and the National Geographic Society. The channel airs non-fiction television programs produced by National Geographic and other production companies. Like History and Discovery Channel, the channel features documentaries with factual content involving nature, science, culture, and history, plus some reality and pseudo-scientific entertainment programming.