Hi<br/><br/>Can you help?<br/><br/>1) She requires <b>positive criticims</b> on this essay. Is the phrase natural? if not, what can best replace it?<br/><br/>2) Which is correct? While the oven <b>is preheating</b>/ the oven <b>is preheated</b> .........<br/><br/>3) She was at peace with herself. Is this sentence natural?<br/><br/>4) If only you had understood me. Is this a sentence? If so, when can I use it?