A、It was not self-sustaining because it stayed in the air for only one minute. B、It partially resorted to the strong and steady

Ask any American who invented the airplane and they would say the Wright brothers, but Brazilians would have a different answer. In the Opening Ceremony of the Olympics on Friday, Brazil continued that claim by honoring Alberto Santos-Dumont, the man they credit with the invention.
    In 1906, Santos-Dumont flew his plane on the outskirts of France and was recognized around Europe as the creator of the airplane. But Orville and Wilbur Wright later proved that their first flight came three years earlier in 1903.
    The question is whether the Wright brothers’ flight should count.
    The opinion of many Brazilians is that the Wrights used a catapult and simply created a glider that could maintain a prolonged fall. In 2003, CNN looked into the conflicting claims.
    Aviation experts in Brazil claim that the Wright brothers needed strong and steady winds to get the " Kitty Hawk" off the ground, leaving no proof that it was able to take off on its own.
    American experts disagree with that claim and say the Wrights’ plane had to have been self-sustaining.
    "Even in 1903 the airplane sustained itself in the air for nearly one minute. If it’s not sustaining itself under its own power, it’s not going to stay up that long, " Peter Jakab of the National Air and Space Museum told CNN.
    Which country really invented the airplane depends plenty on the definition and on the circumstances that the Wright brothers used to get off the ground. The country of Brazil made it clear which side of the debate it is on early in the Opening Ceremony.
    Questions 12 to 15 are based on the passage you have just heard.
    12. What can we learn about Santos-Dumont?
    13. What hinders the confirmation of the creator of the airplane according to the speaker?
    14. Why do Brazilians think that the Wright brothers’ flight don’t count as the first one?
    15. What was the justification that American experts argued for the Wright brothers’ flight?