内容简介
You'llfindtheanswerstohundredsoffascinatingquestionsdboutinventionsinsidethisnewchildren’Sencyclopedia.·Over340fascinatingquestionsandanswers·Datesforkeginventionsataglance·Indexoffamousinventors·Over200photographs·MorethQn250illustrationsJcutawagdiagramsandcartoons