Read the text carefully, then answer the questions!

Cinderella

    Once upon a time, there lived a girl named Cinderella. She lived with her stepmother and two stepsisters. The stepmother and her stepsisters didn't like Cinderella. They treated Cinderella very badly. Cinderella usually did the hardest works in the house; such as scrubbing the floor, cleaning the pot and pan and preparing the food for the family, and so on.

    One day, a ball was to be held by the royal family of the kingdom to find a prince's spouse. Cinderella wanted to go to the ball, but her stepmother asked her to stay at home and do the house works. Cinderella cried. Then there was a fairy godmother standing beside her.

    "Why are you crying, Cinderella?" the fairy godmother asked.

    "Because I want to go to the ball, but my stepmother insists me to stay at home. Besides, I don't have any beautiful dress," said Cinderella.

    Then the fairy turned Cinderella's ugly dress became the most beautiful dress and with slippers. The fairy also turned a pumpkin into a parking coach and the mice became six white horses. Cinderella finally could go to the ball, but she had to come back before midnight before the spell ended.

    At the ball, Cinderella amazed everybody there include the prince. The prince asked her to dance. Cinderella had a wonderful time at the ball. But, all of a sudden, she heard the sound of a clock. The first stroke of midnight. Remembered what the fairy said, Cinderella ran back to go home. But she lost one of her slippers in the ballroom. The prince picked up her slipper and would search for the girl whose foot fitted with the slipper.

    A few days later, the prince proclaimed that he would marry the girl whose foot fitted the slipper. Her stepsisters tried on the slipper, but it was too small for them, no matter how hard they squeezed their toes into it. In the end, the King's soldier let Cinderella try on the slipper. She stuck out her foot and the page slipped the slipper on. It fitted perfectly.

    Finally, she was driven to the palace. The prince was overjoyed to see her again. They were married and lived happily ever after.

How many stepsisters did she have?