The baby will open its mouth twice, the second time with a nice wide mouth, and lean in to grasp the breast.

VOA: special.2010.08.04

You have to stop eating with your mouth open.

你不能再边说话边吃饭了。

have to 实战 - SpeakingMax英语口语达人

Germont looked at Dupin with his mouth open.

VOA: special.2009.12.26

POLITICIANS, it is said, approach every issue with an open mouth.

ECONOMIST: The Tories

The profile photo is the face of a lion with its mouth open, baring its fangs.

CNN: Boston bombing suspect tweeted 'stay safe'

And then I turned around and saw that a managing director was watching with his mouth open.

WSJ: Warning: Banking May Be Hazardous to Your Health