In the 20th century, many scientists thought that the ocean floor was flat. Though we know now that it is not.
Answer:The preoperational stage
Explanation:The preoperational stage is the second stage in Piaget's theory of cognitive development. It start from the age of 2 and last up to when the child is seven.
At this stage a child can manipulate symbols but they don't yet understand concrete logic (literal definition of things and facts of here and now). The reason why they still believe Santa live in North Pole and wear those clothes to keep warm.
