Mary Armstrong was a pretty little girl, but she did not pay attention to her things. She usually left her books and playthings everywhere, and it gave her mom much trouble in picking them up and putting them in the proper places. Some of her books and toys became spoiled（损坏）. Her mom had often told Mary the bad result of being so careless. The growing habit of carelessness would make her unhappy, and sometimes annoy her friends. Even worse, it would be of great harm to her all her life. But Mary didn't listen to her mom. So they argued a lot.
One day, Mary made a beautiful toy, a gift for her best friend's birthday. When her mom asked her to go out into their yard to play, Mary put the toy in her room casually（不经意地）. She ran around and played happily there. An hour later, it was time to go to her friend's birthday party. Mary went back to get the toy. But she couldn't find it anywhere. Finally, she found the toy broken in the corner. At once she realized that Dash, her pet dog had done this, and she was very angry. Carrying the broken toy to her mom, she couldn't help crying.
Mrs. Armstrong asked Mary if she had left the toy in the place where Dash could easily get it, and Mary answered, "Yes, mom."
"Then you should not be irritated, Mary, because the dog does not know it is wrong to play with your toy. I hope this will be a lesson to you hereafter, to put your things away when you finish."
"I will try," said Mary. And her mom promised to repair the toy as well as she could.
