Ответ:

* Mr. Driscoll, who has got a huge collection of old stamps, is my father's boss. (who - refers to Mr. Driscoll)

* Mrs. Sarandon, whose daughter was in the same class as my sister, returned from the USA two weeks ago. (whose - refers to Mrs. Sarandon)

* My boss, for whom I've worked for 20 years, is going to retire next December. (whom - refers to my boss)

* Malindi, which is a popular holiday resort, is in Kenya. (which - refers to Malindi, a place)

* Nicole Kidman, who has made a lot of Hollywood movies, was born in Australia. (who - refers to Nicole Kidman)

* The Beatles, whose name then was The Silver Beatles, first played together at the Cavern Club. (whose - refers to The Beatles)

* Crypto, whose author is Dan Brown, is a novel based on the world of computers. (whose - refers to Crypto, a thing)

* The Eiffel Tower, which was built between 1887 and 1889, is the most famous landmark in Paris. (which - refers to The Eiffel Tower, a building)

* The Olympic Games, which were held at Olympia in ancient times, were first revived in Athens in 1896. (which - refers to The Olympic Games, an event)

* The Smiths, who have just sold their house in the UK, are buying a house in Chicago. (who - refers to The Smiths)