The following books are from the Magic Treehouse series.  These are AR books.

Afternoon on the Amazon

Buffalo Before Breakfast

Civil War on Sunday

Day of the Dragon King

Dingoes at Dinnertime

Dinosaurs Before Dark

Dolphins at Daybreak

Earthquake in the Early Morning

Ghost Town at Sundown

Good Morning, Gorillas

High Tide in Hawaii

Hour of the Olympics

The Knight at Dawn

Midnight on the Moon

Mummies in the Morning

Night of the Ninjas

Pirates Past Noon

Polar Bears Past Bedtime

Revolutionary War on Wednesday

Stage Fright on a Summer Night

Thanksgiving on Thursday

Tigers at Twilight

Tonight on the Titanic

Twister on Tuesday

Vacation Under the Volcano

Viking Ships at Sunrise

The following books correspond to Georgia Performance Standards and do not have AR tests.

Ancient Greece: 40 Hands-On Activities to Experience this Wondrous Age

Clean Planet

Dirt

Dirt: The Scoop on Soil

Down to Earth

Environment at Risk: The Effects of Pollution

Environmental Awareness: Land Pollution

Environmental Awareness: Air Pollution

Environmental Awareness: Water Pollution

Everybody Needs A Rock

Exploring Mountain Habitats

Fight Air Pollution

Habitats

Heat

Heat

Magnets (First Science)

Magnets (Compass Point Phonics Readers)

Magnets: Pulling Together, Pushing Apart

Magnets (First Step)

Poisoned Planet:  Pollution in our World

Pollution and Conservation

Protect Natural Habitats

Soil

Stories in Stone: Rock Art Pictures by Early Americans