他传达坏消息时，脸上带着严肃的表情。

He had a ___grim expression on his face as he delivered the bad news.

他们惊讶地凝视着它，但慢慢地，严肃的面孔被微笑和笑声取代。

They gaped at it with surprise, but slowly the ___grim faces were replaced with smiles and laughter.

宣布裁员后，房间里的气氛变得严肃而悲伤。

The atmosphere in the room was ___grim after the announcement of the layoffs.