When reading a memoir, how can a person recognize themes the author explores?

Dogs make wonderful pets because they keep us happy and healthy, the topic sentence is "dogs make wonderful pets". can someone me write a unrelated sentences to the topic and can be eliminated. need asap

In at least one hundred words, discuss how tradition vs. change is a theme in things fall apart. use evidence from the text to support your answer.

What do u want to know about australia ?