One Tuesday, we got up, had breakfast and got ready for school. We picked up our school bags and went to school. I opened my school bag to get my homework after I went into the classroom and sat down. My school homework needed to be handed in. But it was not there!  I remembered I had put it in my school bag. I thought back to Monday afternoon. I finished my school homework, put it in my school bag, and went out to play softball with the neighbor kids. My sister Sara was not out playing as usual. She read a book inside the house. She must have taken my homework while I was playing softball outside as no kids came inside our house on Monday.      After school I ran to the place where my sister and I usually meet. There was Sara. She didn't seem to be laughing at me. She is good at giving false information.  "Sara, what have you done with my homework?" I asked. She said she hadn't seen it!   "What should I do?" I thought. I waited for a chance to talk to Mom. In Mom ' s room, I cried and shouted: I couldn't help shaking. I told her about my missing school homework. Hearing this, Mom left the room, went into the kitchen hurriedly and started looking in the trash. She pulled my school homework out of the trash!  Mom said, "I' m sorry, Teri. I saw that your school bag was too heavy, so I cleaned it out for you. Your homework didn't look any different from the waste paper which I threw away."      I realized that I had misunderstood my sister. I apologized to her. And I learnt a good lesson from this experience. Why did the writer think it was her sister who had taken her homework?
Because her sister had done that before. Because her sister needed the homework. Because her sister didn't get along well with her. Because her sister was in the house while she was out.