
How do we know about ice ages? Scientists study ice. Scientists study clues from glaciers. Scientists study fossils.
What Do You Think? How did humans live during the ice age?
Photo Credit: Corbin17/Alamy Stock Photo
You can practice reading to your pet. Pets love to … read more
The Hmong are from China and Southeast Asia. Many fled … read more
Do you see the orange fish? This is a garibaldi … read more
© 2026 McGraw-Hill Education. All Rights Reserved.