Magic Tree House
　Mary Pope Osborne is the author/of the Magic Tree House  series.// Jack and Annie are the main characters.// They travel to many places across time/through a magical time-machine tree.// The first book,/Dinosaurs  Before Dark ,/was published in 1992.// Ever since,/more than 40 volumes/have been published.// The series has been translated/into 35 languages/and has sold/more than 140 million copies/worldwide.//
　The series is so popular/because of its plot and educational values.// Readers always want to know/what will happen next/because the stories usually end/with another problem.// They can also learn/about history and cultures.//
　Osborne traveled to many countries/in her twenties.// That experience became the source/of her imagination/to create stories.//