The Old Man and the Sea is a novel by Ernest Hemingway. The book is about an old fisherman, Santiago, whofishes alone. Friendless except for a young boy named Manolin, Santiago has only one remaining purpose in life-to catch a big fish in order to prove to Manolin and to himself that he is still a good fisherman. After eighty-four days of unsuccessful fishing, on the eighty-fifth day Santiago goes far out into the sea, where he hooks a giant marlin. Hestruggles with the fish for two days and nights and finally kills it. Soon sharks appear and attack his fish. The old man fights them off with all his strength but fails to protect his catch. Only the bones of the great fish remain as proof of Santiago’s courage and strength when he returns with it to the harbor. (請依據上述文章,回答第 46~50 題)