In a Period of Time

Everything happens in a period of time.
In a period of time pregnancy occurs.
In a period of time a child is born.
In a period of time a child turns to an adult.
In a period of time life turns to death.
In a period of time the seasons change.
In a period of time the sun rises and sets.
In a period of time a plant grows.
In a period of time in life you get knowledge.