Cells use oxygen to assist in cellular respiration. This type of respiration, called aerobic cellular respiration, converts stored energy into a usable form. The first stage of aerobic cellular respiration, glycolysis, can be performed without oxygen.
A persuasive speech is a specific type of speech in which the speaker has a goal of convincing the audience to accept his or her point of view. The speech is arranged in such a way as to hopefully cause the audience to accept all or part of the expressed view.
1 Ethos is the most important appeal in a persuasive speech.  Factors such as body language, the willingness of the audience, and the environment in which the speech is given, all affect the success of a persuasive speech.