He went on looking at me without any change of expression.

She felt rather than saw the change of expression on the woman's face.

He had not expected that, and I could see his expression change.

I won't say it was easy to show no change of expression.

He looked directly into her eyes and she saw his expression change.

The smile was the first change of expression I had seen.

The black opened the door wide without change of expression.

I looked at his face, trying to catch any change of expression.

He stared at me without any change of expression in his eyes.

He went on without a change of tone or expression.