单项选择题
A.柜体接地应良好;密封、封堵良好,无进水、凝露 B.端子应无过热痕迹 C.油位指示正确
A.1/2 B.1/3 C.2/3 D.3/4
A.1/2-1/3 B.1/3-1/4 C.1/4-1/5 D.1/5-1/6