题目

Sixteen years ago a boy gave me an important gift. It was a smile.     It was the early autumn of my first year at a middle school, and my old school was far away. As a result, no one knew who I was. I was very lonely, and afraid to speak to anyone. Every time I heard the other students talking and laughing, I felt my heart break. I couldn’t talk with anyone about my problems.     Then one day, when my classmates were talking happily with their friends, I was sitting at my desk unhappily as usual. At that moment, a boy entered the classroom. I didn’t know who he was. He passed计算：（-1）2007+（-12）-2×（3）0-|-2|