他用一种茫然的表情盯着我，没有表现出任何认出的迹象。

He stared at me with a ___blank expression, showing no sign of recognition.

老妇人僵住了，她茫然的目光盯着莱拉的方向。

The old woman froze, her ___blank gaze staring in Leila's direction.

听到这个令人震惊的消息后，他的脸完全变得茫然，没有任何情绪。

After hearing the shocking news, his face went completely ___blank, devoid of any emotion.