What Was (what is) 시리즈 30종 세트 (미국판)

What Was the Vietnam War? (What Was?) (미국판)

What Was the Bombing of Hiroshima? (What Was?) (미국판)

What Was Pearl Harbor? (What Was?) (미국판)

What Was Ellis Island? (What Was?) (미국판)

What Was Pompeii? (What Was?) (미국판)

What Were the Salem Witch Trials? (What Was?) (미국판)

What Was the Alamo? (What Was?) (미국판)

What Was the Hindenburg? (미국판)

What Is Congress? (What Was?) (미국판)

What Is LEGO? (What Was?) (미국판)

What Are the Summer Olympics? (What Was?) (미국판)

What Was the Boston Tea Party? (What Was?) (미국판)

What Was the Berlin Wall? (What Was?) (미국판)

What Was the Underground Railroad? (What Was?) (미국판)

What Was the March on Washington? (What Was?) (미국판)

What Was the Age of Exploration? (What Was?) (미국판)

What Was the Ice Age? (What Was?) (미국판)

What Was Hurricane Katrina? (What Was?) (미국판)

What is the Statue of Liberty? (What Was?) (미국판)

What Was the Lewis and Clark Expedition? (What Was?) (미국판)

What Is the World Series? (What Was?) (미국판)

What Was the Battle of Gettysburg? (What Was?) (미국판)

What is the Panama Canal? (What Was?) (미국판)

What Was D-Day? (What Was?) (미국판)

What Was the Age of the Dinosaurs? (What Was?) (미국판)

What Is Climate Change? (What Was?) (미국판)

What Was the Great Depression? (What Was?) (미국판)

What Are the Paralympic Games? (What Was?) (미국판)

What Was the Gold Rush? (What Was?) (미국판)

What Was? : What Is NASA? (What Was?) (미국판)