The first full dress rehearsal of the opening cercmony of the Beijing Olympic Games

问题描述:

The first full dress rehearsal of the opening cercmony of the Beijing Olympic Games
was held ( )at the National Stadium.
选in the secret 还是in secret

选in secret 意为“私下地”内什么,翻译一下呗不好意思,漏了一点“北京奥运会开幕式的第一个完整的彩排在国家体育场私下地举行(不被外人所知)。”