出版说明
To the Teacher
Seps for the Reader
Vocabulary Words and Definitions
Concept I：Nature or People Limit Things That Can Be Done
Nothing Can Move That Fast
New Tools for an Old Science
One-Eyed People and Terrible Monsters
They Were Not Free
The Escape of the Sea Otters
Too Many Lemmings
Favorite Foods from Far Away
Sources of Power
They Were Not Allowed to Fight
A Dangerous Land
Hot Rivers or Cool Rivers
Land of the Tsetse Fly
Diving into Danger
Evil Spirits Lived There
A Passport to Travel
Traveling Animals
Walls of Concrete
Buildings Full of Light
The Curious Brother
Concept II：The Use of Earth，Space and Materials Depends on the Needs of the Users
A Rock with Three Names
Danger in the Sky
Looking for Stars
The Library at Alexandria
A Bathtub Made of Clay
All Roads Lead to Rome
A Seashell Is Its House
Farmers of the Ant World
Artists of the Bird World
The Water Road
Above the Frozen Layer
A New Tree for Ghana
The Wonderful Gift
From Needles to Leather
Tools of Stone
A Village of Coppersmiths
They Gave Their Country New Life
A Desert to Conquer
Windows in the Earth
Written in the Trees
Clues to the Past
A New Treaty
The Road across the Mountains
New Schools for New Lands
Artists Without Brushes
Some Work with Metal
Away to Decorate a Building
The Clever Old Woman of Carcassonne
Concept III: The Success of a Community Depends on Cooperation Among Its Members
Laboratories in Space
Flight of the Friendship 7
News from Venus
From Votes to Notes
Husking the Corn
Working Together Was Fun
Beavers Share the Work
Together in the Cold
Strange Partners
Who Runs a Factory?
Food for All
Defeating the Locusts
A Club for Everyone
Sewing Together
Clubs for Boys and Girls
Gaining by Sharing
A Peaceful Village
Everyone Helps in the Congo
Stories the Whole World Tells
Up the Highest Mountain
Predicting E1 Nifio
Letters around the World
Saving the Seals
Checking on the Weather
The Fort That Became a Museum
The Flood at Florence
Saving the Treasures
The Weaving Contest
Charts for Record Keeping
