A、By removing the bottom of the basket. B、By lowering the position of the basket. C、By simplifying the complex rules. D、By alter

One winter day in 1891, a class at a training school in Massachusetts, USA, went into the gym for their daily exercises. Since the football season had ended, most of the young men felt they were in for a boring time. But their teacher, James Naismith, had other ideas. He had been working for a long time on the new game that would have the excitement of American football. Naismith showed the men a basket he had hung at each end of the gym, and explained that they were going to use a round European football. At first everybody tried to throw the ball into the basket no matter where he was standing. "Pass! Pass!" Naismith kept shouting, blowing his whistle to stop the excited players. Slowly, they began to understand what was wanted of them.
    The problem with the new game, which was soon called "basketball", was getting the ball out of the basket. They used ordinary food baskets with bottoms, and the ball, of course, stayed inside.
At first, someone had to climb up every time a basket was scored.
    It was several years before someone came up with the idea of removing the bottom of the basket and letting the ball fall through. There have been many changes in the rules since then, and basketball has become one of the world’s most popular sports.
Questions 23 to 25 are based on the passage you have just heard.
23. What did Naismith do to entertain his students one winter day?
24. According to the speaker, what was the problem with the new game?
25. How was the problem with the new game solved?