On a sunny Monday here in the U.S. capital, Secret Service agents patrolled with dogs on the sidewalk outside the White House, while other agents could be seen on the rooftop. 周一阳光明媚,在美国首都,特勤局特工牵着警犬在白宫外的人行道巡逻,另外还有一些特勤人员在屋顶上巡逻. __________________________ The presidential security agency is investigating how the intruder scaled the fence last Friday. 国家安全局正在调查这名非法闯入者是如何在上周五爬过栅栏的. I'm Michael Lipin in Washington. That's the latest world news from VOA. 迈克尔-李平在华盛顿为您报道. 这里是美国之音最新全球新闻.