资源介绍：
美国国家地理少儿分级阅读L2级高清PDF+配套MP3音频，总计25本PDF和MP3音频
美国国家地理分级阅读L2级适合6-8岁
绘本目录：
01-Frogs
02-Wolves
03-Sea Turtles
04-Deadly Predators
05-Bees
06-Penguins
07-Pandas
08-Tigers
09-Prehistoric Mammals
10-Weird Sea Creatures
11-Manatees
12-Alligators and Crocodiles
13-Cheetahs
14-Snakes
15-Saving Animal Babies
16-Dolphins
17-Rocks and Minerals
18-Planets
19-Coral Reefs
20-Mummies
21-Barack Obama
22-Abraham Lincoln
23-George Washington
24-Thomas Edison
25-Alexander Graham Bell
