That39;s the boy _______ father is a pilot.Cate Blanchett, _______ stars

Thats the boy whose father is a pilot. (Whose - чей)

Cate Blanchett, who star in "The Lord of the Rings", is a great actress. (Можно было бы использовать "whom", но британцы так изредка разговаривают и превосходнее "who")

The book that you borrowed is mine. (Тут that - которую)

31st October, when Halloween takes place,  is my favorite day. (When - когда)

Minsk, where my brother was born,  is the capital of Belarus. (Where - где).