于140℃烘20分钟,加水搅拌后变为具有黏性的固体药材的是()
A.朱砂
B.雄黄
C.信石
D.石膏
E.芒硝
参考答案:D
解析:[知识点] 矿物类中药——石膏
The ______ Approach emphasizes on natural communication rather than formal grammar study and is tolerance of learners’errors.
计算(a2)3=______.