昨晚，那位喜剧演员的新段子没能逗乐观众。

The comedian's new material ___fell ___flat with the audience last night.

该公司雄心勃勃的营销活动不幸未能达到预期效果。

The company's ambitious marketing campaign unfortunately ___fell ___flat.

她在严肃会议上的讽刺性评论没有引起共鸣，反而造成了一阵尴尬的沉默。

Her sarcastic comment during the serious meeting ___fell ___flat and created an awkward silence.