人们是怎么知道地球是圆的的？你也许会说是哥伦布航海发现的，但其实远在古希腊时期就有了地球是圆的的理论。 从船上的?t望台能看到在甲板上看不到的远方，月相变化，时差的产生，不同地方的人能看到不同的星空等等，这些都表明地球是圆的。 这本英语原版科普绘本提供了丰富有趣的知识，穿越历史，进入太空，启发孩子观察、思考有关地球形状的现象与知识，培养孩子独立思考的精神。 书后有简单的小实验，引导孩子自己动手、观察。
Great herds of zebra thundering across the Africanplain…fragile butterflies traveling unbelievable distances…familygroups of whales coursing through the waves. Many kinds of animalsmake annual migrations, and their stories reveal incrediblestrength and will to survive. These treks are magnificentlydocumented in Great Migrations, the children’s illustratedcompanion to the upcoming 7-hour National Geographic televisionspecial of the same name. Created for the huge audience of young animal lovers—and for thenation’s schools, where migration is taught as part of the corecurriculum—this book spotlights wild creatures of highest interestto children. Action-filled photo spreads deliver immense "wow"appeal as animals vault over obstacles and escape the clutches ofpredators. Info-graphic spreads pack in the fascinating facts, withat-a-glance information on where, why, and how animalsmigrate. Throughout the coverage, this timely book addresses the effect ofclimate change on animal migrati
