When you use critical thinking while making inferences and drawing conclusions, you need to be confident of your
a.) opinions
b.) predictions
c.) assessments
d.) guesses
e.) hypothesis

There are many techniques that can contribute to the memorability of a speech, for example stressing the main points and explaining them  well, linking the ideas in a logical way and providing a strong conclusion.

One technique that does not support memorability is shouting loudly key words: they might remember you but not the content of the speech.