化简 $\frac{m^2}{m-n}+\frac{n^2}{n-m}$ 的结果是（　　）

  Did you have a good time at the party?
  Yes, indeed. It's years _____ I enjoyed myself so much.

①转化为现实生产力是科技创新价值的重要体现

②不断发展的社会需要是科技创新的重要动力

③科技创新以思想观念的创新为先导

④科技创新总是通过吸收、改造传统技术而实现

    Look at the picture. Who is the girl? She is my friend. Her name is Alice Black. She is an English girl.

    Alice has a big family. Her grandparents have two daughters and one son — her father. Alice lives with her grandparents, parents, two brothers and one sister. Alice has two dogs — Bobby and Tony. Bobby is black and Tony is white. Alice likes them very much. Alice is a middle school student. She has a good friend at school. Her name is Helen. They are cousins, too.

读课文《小鹿的减法》，找出文中的成语（两个），并写在横线上。

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