用原子吸收光谱法测铜，对油脂类样品的处理方法是（）
A.加10ml石油醚，用硝酸（10%）提取2次，合并硝酸液，定容
B.加10ml石油醚，用硫酸（10%）提取2次，合并硫酸液，定容
C.加10ml石油醚，用盐酸提取2次，合并盐酸液，定容
D.加10ml石油醚，用磷酸提取2次，合并磷酸液，定容
E.加10ml石油醚，用乙酸提取2次，合并乙酸液，定容
参考答案：A
We often see dogs always put their tongues(舌头)out in summer. But 1 the dogs didn’t do so. Long long ago, the dog was very bad .He 2 did a good deed. One summer day the dog 3 into a forest. 4 he saw the forest was beautiful and clean , a 5 idea came to him. Then he brought 6 dirty things to the forest and put 7 everywhere. What he did was 8 by a monkey who hid 9 a big tree. He didn’t tell anyone 10 the dog did because 11 did not know why the dog did so. Several days 12 ,it got hotter and hotter , and the dirty things became rotten(腐烂).The air smelt 13 . Many animals fell ill. All the other animals became angry and tried 14 who had done it and punish him. The money knew 15 bad the dog was. So he 16 the other animals the truth. They catch up with the dog and 17 him eat all the dirty things and 18 the forest clean. After that the dog 19 honest. To remember this, he put his tongue out in 20.
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