unnecessary foreign keys

[Wiss ab]

in mysql workbench, once i create the tables i do reverse engineer to create relationships then i notice that he create unnecessary primary foreign keys.

ex: create a table hotel, and table class: 1:n (a classe may have many hotels)
then i create table room : 1: n (an hotel may have many rooms)

now the pbm is on table room he create automatically hotel_class_ClassID and put it as PK !

thanks