It noticed his expression and put its head on one side.

She noticed my expression and suddenly changed her own.

She noticed his expression, which must have been interesting.

Too busy lighting a cigarette, she didn't notice his expression.

Rachel, on the other hand, didn't seem to notice his expression.

Kit noticed his extraordinary expression, too, but she put a different interpretation on it.

He had noticed her expression and his own was thoughtful.

Mel noticed her expression and pressed his eye to the hole.

She noticed my puzzled expression, and explained, "That's when you don't answer a question directly."

But David did not seem to notice his wife's expression.