Ladder encyclopedia knowledge base 600 + [audio bedtime select]

nearly 600 ladder encyclopedia sound knowledge, is 50000 minutes long speech
17 categories include 9:28, history, animals, science, character and so on
support classic classification, keyword search, a button to enter a child's love to hear the story of the painted
Including:
X-ray
gravitation
Flightless bird
East Africa
amphibians
Denmark
The crow
instruments
books
cloud
Alexander the great
Asian wildlife
The Assyrian empire
Human body
The human society
Human evolution
Code and password
Israel
penguins
Iran and Iraq
Itec Russ candy man
Elizabeth I
Immune and lymph system
Rabbit and the hare
Military aircraft
warships
agriculture
Agricultural history
Winter sports
hibernate
Glaciers role
Julius Caesar
La Wei and other insectivorous this animal
Force and motion
Caribbean
Canada
Canadian history
animals
zoo
Animals of the migration of
Animal flight
North American history
North American wild creatures
medical
The sun and the solar system
Olaf MeiKeRen
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