不能用作测定含卤素及含金属有机药物前预处理的方法是()。
A.凯氏定氮法
B.碱性氧化法
C.氧瓶燃烧法
D.碱性还原法及碱熔融法
E.直接回流法
参考答案:A
— Why do you look so sad?
— With so many problems________,I'm in a difficult situation. [ ]
A. settled
B. remained to settle
C. being settled
D. remaining to be settled
简述信托形成的条件。