下列哪项检查对肾前性急性肾衰竭与急性肾小管坏死鉴别诊断最有意义？（）
A.尿钠含量
B.尿量
C.血尿素氮
D.血肌酐
E.尿pH值
参考答案：A
适应性最广的毛坯种类是（）。
A、铸造
B、锻造
C、粉末冶金
D、型材
Project sponsors have the GREATEST influence on the scope, quality, time, and cost of the project during the ______ .
A．concept phase
B．development phase
C．execution phase
D．close-down phase
