U.S. President Barack Obama and Republican challenger Mitt Romney are preparing for their first post-convention debate of the 2012 presidential race. After several days of preparation in his home state of Massachusetts, Romney arrived Monday in Denver, Colorado, the site of Wednesday's debate. Mr. Obama will spend another day of preparations in Nevada. For more on the U.S. presidential campaign, visit our website voanews.com.美现任总统巴拉克. 奥巴马与共和党总统候选人米特. 罗姆尼目前正在准备2012年总统竞选的首场辩论.在家乡马萨诸塞州进行数日准备后,罗姆尼于周一抵达了科罗拉多州丹佛市--周三辩论的举办地.而奥巴马先生将在内华达州多停留一天做准备.预知更多美国大选新闻,请访问美国之音网站. __________________________________.The agent was shot today while on patrol in the town of Naco, Arizona. Authorities have not yet released their identities.该警员今天在亚利桑那州纳可镇巡逻时遭到枪击.目前官方仍未透露枪击受害者的身份.