阅读短文，从每小题所给的四个选项中，选出能回答所提问题或完成所给句子的最佳答案。Martin Strel is a swimmer, best known for swimming the world's big rivers. He was born in 1954. He taught himself to swim when he was six and became a professional (职业的) swimmer in 1978. Martin holds Guinness World Records for swimming the Danube River, the Mississippi River, the Yangtze River and the Amazon River.
Of all his achievements, the greatest is his Amazon River swim. The Amazon is known as the largest and most dangerous river in the world. Several swimmers had tried to swim it, but all failed. Martin decided to go all out and make history. He wanted to show the world that people could achieve their dreams with hard work and perseverance (毅力). On April 7th, 2007, Martin Strel completed his Amazon River all the way from Atalaya (Peru) to the Atlantic Ocean at Belem (Brazil). He struggled (奋战) with the river for 66 days and swam 3, 274 miles in total. He became a worldwide hero.
Many people still cannot believe what he has done so far, so that is why they sometimes describe him as "Fishman", "Human Fish" or even "the Craziest Man in the World".
In 2009, American filmmakers produced a documentary (纪录片) called Big River Man. And the book, The Man Who Swam the Amazon, has been sold in many countries. It tells us an inspirational story of perseverance and hard work, which has encouraged many people.
Martin doesn't swim for money. Instead, he swims to teach people about the importance of keeping water clean.
Martin has always been looking for the challenges (挑战) of the impossible. What is his next?
