三相四线制
参考答案：
引出中线性的星形接线，连同三根端线（火线）共四根电源线，这种接线叫三相四线制。
_______in thought, he didn't notice that the teacher was right in front of him. [ ]
A. Losing
B. To lose
C. Being lost
D. Lost
促进ADH分泌的药物()易引起乳酸血症的药物()
A.二甲双胍
B.氯磺丙脲
C.格列本脲
D.格列吡嗪
E.甲苯磺丁脲
