Answer:
to encourage listeners to think about the possible answers to the questions
Step-by-step explanation:
The questions at the end of the speech have the main function of stimulating the listeners' reasoning about the theme of the speech and the arguments that were expressed with the speech. In other words, we can affirm that with this strategy the author intends to highlight the importance of the questions surrounding the theme and encourage listeners to think about the possible answers to the questions expressed.