the author says that in dystopia teenagers see echoes of a world that they know what is the connotation of the word echoes

The echoes of the world they know connotes those things the teenagers have known to be true but don't want to agree with them examples of this is their thinking about rules which some say are bad and going to school that will keep them in a place.

The story gives them an analogy of what they do not want to hear as it start with a happy beginning but the end tells the consequences. Therefore it echoes truth back to them.