One day, a poor boy who was trying to pay his way through school by sending newspapers door to door, was so hungry that he decided to beg for a meal at the next house.      However, he lost his nerve when a lovely young woman opened the door. Instead of a meal he asked for a drink of water. She thought he looked hungry so she brought him a large glass of milk. He drank it slowly, and then asked, "How much do I owe you?"      "You don't owe me anything," she replied. "Then I thank you from the bottom of my heart." With these words, Howard Kelly left that house.      Years later the woman became badly ill and was finally sent to the hospital in a big city. Dr. Howard Kelly, now famous, was called in. When he heard the name of the town she came from, a strange light filled his eyes. Dressed in his doctor's clothes, Dr. Kelly went into her room and recognized her at once. From that day on, he gave special attention to her, and decided to do his best to save her life.      At last the woman was saved. Dr. Kelly asked the business office to pass the final bill to him. He looked at it and then wrote something on the side. The bill was sent to the woman's room. She was afraid to open it because she was sure that it would take the rest of her life to pay for it off. Finally she looked, and the note on the side of the bill caught her attention. She read these words:         "Paid in full with a glass of milk, Dr. Howard Kelly."      Tear of joy flooded her eyes. After Dr. Kelly knew who the woman was, he   _  .
began to take good care of her himself decided to try his best to save her told her she once gave him a glass of milk asked for her bill and paid it off at once