Exercise 7 Insert the correct possessive pronouns.
Nick: Whose sunglasses are these?
Mary They're Amy's, I think. Yes, they're ... .
Paul: Whose baseball cap is this?
Amy: That's ... too! Thanks.
Mary: Ugh! Whose dirty towel is this?
Nick: Ask Paul. I think it's
Paul: Yes, it is. Thanks. You've got a great T-shirt, Amy!
Mary: Thanks. I borrowed it from my big sister. So it's ... really.
Nick: What about this umbrella?
Paul: Don't be silly, Jason! You brought it, so it must be ...
Mary: Does this beach ball belong to us?
Nick: No, it isn't ... Those kids over there were looking for a ball, so it's ...​

Nick: Whose sunglasses are these?
Mary: They're Amy's, I think. Yes, they're hers.

Paul: Whose baseball cap is this?
Amy: That's mine too! Thanks.

Mary: Ugh! Whose dirty towel is this?
Nick: Ask Paul. I think it's his.

Paul: Yes, it is. Thanks. You've got a great T-shirt, Amy!
Mary: Thanks. I borrowed it from my big sister. So it's hers really.

Nick: What about this umbrella?
Paul: Don't be silly, Jason! You brought it, so it must be yours.

Mary: Does this beach ball belong to us?
Nick: No, it isn't ours. Those kids over there were looking for a ball, so it's theirs.

Explanation:
In the first sentence, the possessive pronoun "hers" is used because it refers to Amy, indicating that the sunglasses belong to her.
In the second sentence, the possessive pronoun "mine" is used because Amy is saying that the baseball cap belongs to her.
In the third sentence, the possessive pronoun "his" is used because it refers to Paul, indicating that the dirty towel belongs to him.
In the fourth sentence, the possessive pronoun "hers" is used because it refers to Mary's big sister, indicating that the T-shirt belongs to her.
In the fifth sentence, the possessive pronoun "yours" is used because it refers to Jason, indicating that the umbrella belongs to him.
In the sixth sentence, the possessive pronoun "ours" is used because it refers to Mary, Nick, and possibly others, indicating that the beach ball does not belong to them. Instead, it belongs to the kids mentioned.

Step-by-step solution:
1. Read each sentence carefully to understand who the possessive pronoun refers to.
2. Identify the person or people who the possessive pronoun should represent.
3. Choose the correct possessive pronoun based on the person or people identified in step 2.
4. Insert the possessive pronoun in the sentence.
5. Repeat steps 2-4 for each sentence to ensure the correct possessive pronoun is used.