美国常用英语俚语:Uncle Sam
【句子对照】July 4th is the Independence Day in the United States. Happy Birthday, Uncle Sam! 7月4日是美国的独立日，生日快乐，山姆大叔！
【关键俚语】Uncle Sam英：The U.S. government; a patriotic figure who symbolizes the United States.中：山姆大叔，美国政府
