The mad dog was foaming at the mouth.

疯狗口吐白沫。

He stood there foaming at the mouth. I’ve never seen anybody so angry.

站大发雷霆，我还从没见过有人生这大气的。

He is foaming at the mouth about the committee's decision.

正为委员会的决定大发。

He looked like a madman, foaming at the mouth.

口吐白沫, 看上去像个疯子。