In what sense is Descartes' reasoning considered circular and thus invalid?

The primary sense in which Descartes' reasoning can be considered circular is that he deduces the existence of God from what he calls 'clear and distinct perceptions' but argues for the reliability of these perceptions from the existence of God.

Explain how different narrative structures support the tone and/or moral of particular literary works.

The narrative structure of a literary text can be employed in order to reinforce or contrast the plot so as to provide the reader with insight into the nuances of authorial intention. For example, a third person narrative structure typically provides the reader with a sense of distance so that they may critically assess the characters and plot of the story.

Consider and explain the effect of rhetorical devices such as repetition in written English.

Depending on the context, rhetorical devices and particularly repetition can have a powerful effect on the impact and reception of written English. For example, both poetry and persuasive writing often employ repetition in order to reinforce the authors point of view and either compel or convince the reader to remember the concerns expressed.