Answer:
1. diversity is variety, or being diverse.
Step-by-step explanation:
ex: my school is very diverse because we have people from all ethnicities and genders.
2. diversity might matter in the fact of public speaking because there isn't one set group of listeners to your public speech so you have to be open to all groups (being diverse)
3. one technique or thing to think about when you're presenting for diverse audiences is you have to keep bias out of your speech. you also have to have a sort of idea on how each group of listener would react to what you say because some groups May react differently.
hope this helps! <3