Answer:
Etiquette is learned
Step-by-step explanation:
When the author says this he is trying to say that Etiquette is learned and can be modified or adjusted, it does not always stay the same. This is because as times change so does society. Meaning that the customs and beliefs of society change as well, such as what is considered polite behavior. As these changes occur so does Etiquette and the people adjust and learn this new Etiquette.