What are three references in the story to traces marks left behind by objects or actions?

Three references in the story to traces of marks left behind by objects or actions are

1 the dents of the bicycle pump on the wall where the bicycle had once been chained

2. the marks of old footprints that seem to lead back to the room, suggesting someone else has been there

3. the impressions left by the man’s body where he has slept in the sand