Please help me. Are these sentences correct?<br/><br/>1. When <u>realizing </u>that this was not ordinary, he tried not to damage it.<br/><br/>2. When he <u>realized</u> that this was not ordinary, he tried not to damage it.<br/><br/>3. When <u>having realized</u> that this was not ordinary, he tried not to damage it.<br/><br/>Thanks for your help.