Subject & Object pronouns, possessive adjectives & pronouns

I found that cookie! It’s (a)   !

This book is yours. It is (a)   book.

They are looking for (a)   classroom.

Mr. Smith likes (a)   new job.

My sister and I bought that car. It is (a)   car.

Mrs. Brown took (a)   son to a hospital.

Our teacher gave (a)   a grammar test.

(a)   forgot to do her homework.

My cat likes to play with (a)   new toy.

It’s my sister’s birthday today. (a)   is eighteen years old.