学进去

David was a little boy. He ________ four years old. One day his mother ________ him to see his grandmother. His grandmother's home was very far ________ them, so they went there ________. There ________ only a few(一些) people on the bus. They all sat on ________ seats. David was ________. He looked out of the window and talked with his mother.

A moment later(一会儿以后), David started running on the bus. He ran and ran(不停地跑来跑去). "________ are you always running? Please sit ________." His mother said. "I want to see my grandmother ________. I want the bus to go faster," David answered.