Here are the correct answers to your exercise:1. The dog **that** Robert bought has just had six puppies. (D)2. The actor **whom** I admire the most is Colin Firth. (D)3. Emma, **whose** sister is an actress, is going on holiday to Hollywood. (N)4. The country **where** my Dad was born is in South America. (D)5. The book **that** I'm reading is about China. (D)6. This jumper, **which** I bought in Ireland, is pure wool. (N)7. His own town, **which** is very small, is near Berlin. (N)8. His uncle, **who** is a millionaire, owns a house in the Bahamas. (N)Defining relative clauses provide essential information to identify the person or thing we are talking about and do not require commas. Non-defining relative clauses provide extra information that can be left out without affecting the meaning of the sentence and are separated by commas.