Question 1 :
Packaged data models are meant to be exactly right straight out of the box.
Question 2 :
An action assertion is a statement that expresses some aspect of the static structure of the organization.
Question 3 :
A supertype can only have only one subtype.
Question 4 :
There is cardinality on an EER between the supertype and subtype.
Question 5 :
A subtype discriminator of the supertype is an attribute whose values determine the target subtype(s).