Question $3(10$ points$)$Question $1(10$ points$)$

We consider the ERD below describing a Book in a library system:

Check all that apply. Why did we split Book into Book and BookCopy to represent a

book in a library?

All Book$($s$)$ have the same ISBN and ISBN cannot be a key for a BookCopy.

A BookCopy has additional attributes with respect to a Book such as its status in

the ${?}^{\text{M}\text{i}\text{b}\text{r}\text{a}\text{r}\text{y}\text{.}}$

We want to avoid redundancy when we transform the ERD into relations. $T$

A BookCopy is a physical book while a Book captures all the features of a book

including isbn, title and pubyear.

Question $2(10$ points$)$

On an ERD, a double ellipsis represents a set$-$valued attribute.

True

False

We consider the following ERD.

Does it make sense to have an attribute profid in Department?

True

False