In the past, why did people depend on oral tradition for their stories?

Does anyone know the answer to the question?

What is the topic sentence of paragraph 5 of the passage?

Read this sentence: while on vacation, i often relax by reading one of myfavorite books, go to the movies, or swimming in the pool. which revision corrects the parallel structure error? a. while on vacation, i often relax by reading one of my favoritebooks, going to the movies, or swimming in the pool. ob. while on vacation, i often relax by reading one of my favoritebooks, going to the movies, or swim in the pool. oc. while on vacation, i often relax by reading one of my favoritebooks, i like to go to the movies, or go swimming in the pool. od. while on vacation, i often enjoy relaxing by reading one of myfavorite books, go to the movies, or swimming in the pool.