Final answer:
The child-centered approach is based on the knowledge that normal children learn language by actively exploring their environments and communicatively interacting with others.
Step-by-step explanation:
The approach based on the knowledge that normal children learn language by actively exploring their environments and communicatively interacting with others is the child-centered approach. This approach emphasizes the importance of children's natural curiosity and engagement in their learning process. It recognizes that children learn best through hands-on experiences and meaningful interactions with their surroundings and peers.