Choose the correct relative pronoun to complete the sentences. 1.Mr. Smith, (who / that) is my friend, has worked in the National Reserve for five years. 2 The Askania Nova, (which / that) I visited last year, is a great home for wildlife. 3 I finished reading an article about climate change (that / who) was really interesting.4. An environmental conference (which / who) will take place in Berlin next Monday is rather important. 5 I finished reading the book about nature, (which / whose) was made into a film. 6 Pesticides are chemicals (that / who) are used for killing insects.