gape

n. 裂口,张嘴
v. 裂开,张嘴

She gaped at the tall man, not believing that he was her younger brother.

她张嘴呆看着那个高个子，不相信他就是她的弟弟。

Dont gape : its rude!

别张著嘴傻瞪著, 太不礼貌了!