一吨废手机，经过加工提炼后，能产生300到400克的黄金，500克左右的白银。我们要让大量可利用的废手机进入正规回收企业，让“城市污染”变成“城市矿产”。绿色消费的核心是（    ）

   The girl is my friend. She is thirteen 1 old. She is 2 with long legs. She 3 long hair, but she has a 4 face like an apple. She has two big black eyes and small ears. 5 mouth is big, but her nose is6. She likes red, but now she is 7a yellow skirt and brown 8. She is a nice girl. She and I9 good friends. 10 is she? She is Linda.

达尔文进化论的核心内容是（　　）