She looked up at his face; its expression gave nothing away.

The expression in his eyes gave her the courage to go on.

He looked up quickly, but her expression gave him pause.

While he was eating, his expression could not give him away.

He was looking dead ahead, his expression giving nothing away.

If they tried, an expression or posture would give them away.

He looked away for a moment and his expression gave him the appearance of a little boy.

His expression gave little hint of what he was thinking.

His expression gave nothing away, not that I expected it to.

He stared at her for a moment longer, his expression giving little away.