Hi. Please help me with these. Do you need prepositions for the sentences below?<br/><br/><i>1. His birthday is January XX.</i><br/><br/><i> His birthday is <u>on</u> January XX.</i><br/><br/><i>2. Christmas is December 25.</i><br/><br/><i> Christmas is <u>on</u> December 25.</i><br/><br/><i>3. Veteran's Day is (I don't know when).</i><br/><br/><i> Veteran's Day is <u>on</u> (I don't know when</i>).