今天我们要学的词是 unannounced. Unannounced 形容词，事先未经宣布的。U.S. Defense Secretary Jim Mattis made an unannounced visit to Afghanistan. 美国国防部长马蒂斯对阿富汗进行了事先未经宣布的访问。U.S. Vice President Pence made an unannounced visit to the demilitarized zone between North and South Korea during his 10-day Asia trip. 美国副总统彭斯在十天亚洲之行中对朝鲜半岛非军事区进行了事先未经宣布的访问。好的，我们今天学习的词是 unannounced, unannounced, unannounced...