阅读短文，并按照题目要求用英语回答问题．Bornin1949，DianaNyadtookanearlyinterestinswimmingasasportandwasaFloridaStateHighSchoolswimmingchampion．Likemanyyoungathletes，shehadOlympicdreams，butaseri
阅读短文，并按照题目要求用英语回答问题．
Born in 1949，Diana Nyad took an early interest in swimming as a sport and was a Florida State High School swimming champion．Like many young athletes，she had Olympic dreams，but a serious illness kept her from competing in the Games．The disappointment didn’t stop her from going forward．Instead，she became interested in marathon swimming．A brilliant athlete，she was well-conditioned for spending long periods of time in the water．As a long-distance swimmer，she would compete against herself and theobstacles presented by distance，danger，cold，and exhaustion．
For ten years Nyad devoted herself to becoming one of the world’s best long-distance swimmers．In 1970，she swam a ten-mile marathon in Lake Ontario，setting the women’s record for the course．In 1972she set another record by swimming 102.5miles from an island in the Bahamas to the coast of Florida．Then she broke a third record when swimming around Manhattan Island in 1975．
Nyad attempted to swim the distance between Florida and Cuba in 1978．Though the span of water is less than 100miles wide，it is rough and dangerous．After battling the water for two days，she had to give for the sake of her own health and safety．Even so，she impressed the world with her courage and strong desire to succeed．For Nyad her strength of purpose was just as important as reading Cuba．That is how she defined success．It did not matter that her swim came up short； she believed she had touched the other shore．
When Nyad ended her career as a swimmer，she continued to try new things---travelling the world as a reporter，writing books and giving public speeches about her life．Diana Nyad works to inspire others，just as she did when she swam the waters of the world．
56．What prevented Nyad from taking part in the Olympic Games？（No more than 5words）
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57．What does the underlined word“obstacles”mean？（1word）___
58．What achievement did Nyad make in 1970？（No more tha