Charles Darwin, born in 1809, was a great biologist 16 who is best known for his theory about the evolution of plants and animals. During a five year journey on a naval survey ship, HMS Beagle, Darwin visited the Galapagos Islands off the coast of South America. There he saw plants and animals 17 which were found nowhere else in the world. Darwin knew that even animals of the same type had slightly different features. He suggested that the animals 18 whose features made them best suited to their surroundings were most likely to survive. Therefore, these features would be passed on to their young. In this way a population of animals would slowly change or evolve.Darwin published his ideas in 1859 in The Origin of the Species. The book caused an uproar and many people didn’t understand 19 what Darwin was saying. They thought, wrongly, 20 that he was claiming that humans had descended directly from apes. Darwin died in 1882, aged 73. 16. A who B whose C that D what 17. A whose B which C who D whom 18. A what B who’s C whose D who 19. A what B that C which D who 20. A whose B what C who D that
