metaphors compare two concepts that at first seem unrelated
The titanic crew was divided into different groups according to the tasks and jobs they developed. The main differences/divisions were the following:
Ship's officers
Deck crew
Engineering crew (responsibles for keeping the engines running)
Victualling crew (they provided the services for the occupants of the ship)
Restaurant staff
Postal clerks (in charge of the incoming and outcoming mail)
Guarantee group (were there to find any unfixed problems)
Ship's orchestra
Some different people sacrifice people as they think it will bring them good luck.
A subject pronoun is a personal pronoun that is used as the subject of a verb.