1、The audience sat openmouthed, unable to believe what they were seeing on stage.
观众们张开嘴巴坐着，难以相信他们在舞台上看到的一切。

2、She stood, openmouthed, as the magician pulled a rabbit out of his hat.
她张开嘴巴站着，看着魔术师从帽子里拽出一只兔子。