合成维生素D的组织器官是（）
A.皮肤
B.骨骼
C.肝脏
D.肾脏
E.小肠
参考答案：A
— The King’s Speech has become the 83rd Oscar winner. I like it very much.
— Me, too. I think this is ________ film I’ve seen.
A．a better
B．the worst
C．a worse
D．the best
芳烃抽提的基本目的是什么？芳烃与非芳烃的分离可以分为哪几个步骤？
