Shirley was a shy girl and she seldom（很少） answered questions in our class. She was afraid of making mistakes. Sometimes she couldn't finish her homework because she didn't want to make any mistakes. Nothing changed until Mr. Smith，a new teacher，came to our class.
One morning，Mr. Smith asked Shirley to answer some questions. After a while，she was in tears（哭了） because she gave the wrong answers. At that time，Mr. Smith took out a small box. The box was filled with erasers. "Look，Shirley，" he said，standing next to her. "I have something to show you. " He took out the erasers and put them on the desk.
"Look at these erasers，Shirley，" he continued. "Do you know why they become smaller and smaller?That's what you must learn everybody makes mistakes，but they can be valuable （珍贵 的）experience and teach you something important. "Then he left one eraser on Shirley's desk.
From then on，Shirley changed a lot. Instead of being shy，now she is active and confident（自信的）. She isn't afraid of making mistakes any longer.
