Question

When you give an oral report, why should you use vocabulary related to your topic?

Some of your listeners will get bored if you don’t.
It will help you remember what you’re supposed to say.
Your listeners will believe that you know a lot about the topic.

Answer 1

I believe it is the third one “your listeners will believe that you know a lot about the topic” this is because when you use vocab it shows that you read, studied and understand the topic you are presenting.