具有“绿色水库”之称的生态系统是(     )

经过两次翻折(对称轴平行)后得到的图形，可以看成是原图形经过一次____得到的。

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     My name is Chen Yang. I'm twelve years old. I'm a Chinese student.

     There are four people in my family—my father, my moth er, my brother and I. My father is a doctor at the City Central Hospital and my mother is a theatre manager. My brother is a student, too. He is thirteen. We are in the same school, but not in the same class.

I like English very much. I can speak a lot of English. I want to have an American pen friend. Let's be friends, OK? Please write to me. My address is No. 22 Middle Sc hool, Hunan, China. My email is Cheny @ hotmail. com.

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