A：x2﹣9=（x+3）（x﹣3）
B：x2+5x﹣1=x（x+5）﹣1
C：x2﹣4+3x=（x+2）（x﹣2）+3x
D：（x+2）（x﹣2）=x2﹣4
— Do you think my classmates will laugh at me?
— Maybe. But I think you are right.
广为采撷——摘录课文中富于哲理的句子，课外收集赞颂“年轻精神”的名言警句。
