Part of the assignment is to consider the circumstances in which a speech on the issue of virtual reality might be delivered.
For example, you might deliver such a speech at a science fair at school. In this case, the speech is addressed to other high school students and the language and content should be simple and easy to follow. You should also use devices to connect with the audience, such as relevant cultural references or jokes.
Another circumstance in which the speech might be delivered is to university students of IT and Computer Sciences. In this case, the language can be more advanced and detailed since they are accustomed with the vocabulary of technology.
A more likely medium for delivering a speech on VR tech is a TED Talk. TED Talks are annual conferences in which various speakers deliver short, powerful and inspiring speeches on topics like technology and science, as well as on economic, cultural, and politic...