
Sir Isaac Newton was the first person to study gravity. He was sitting under an apple tree. An apple fell from the tree and hit him on the head. He discovered that gravity made things fall to Earth.
Photo Credit: McGraw Hill
A microscope is another tool. It is also used to … read more
Wimbledon is a tennis competition. It takes place in England. … read more
Amphibians live part of their lives in water. Adults lay … read more
© 2026 McGraw-Hill Education. All Rights Reserved.